Lets Talk of the Specifications First:

>Operating System
Series 60 (3rd Edition) SmartPhone (Symbian version 9.1)
>Weight
164gms
>Size
113.1x55.2x22 mm
>Network Bands
GSM 850/900/1800/1900 plus 3G(WCDMA):384 Kbps EDGE: Class 10,236.8 Kbps
>Display
TFT,256 k colors;176x208 pixels
>Battery
Stand By 170-190 hrs TalkTime 3-4 hrs
>Memory
4Gb Harddrive(for Music etc,.);30 Mb for Contacts,calendar.
>Connectivity
Bluetooth Yes 1.2
Infrared No
USB Yes 2.0
WLAN 802.11b/g
>Messaging:
SMS,MMS,Email,Instant Messaging
>Camera
Camera:2 Mega Pixel with 20x digital zoom ;1600x1200 pixels.
>Music Compatibility
Yes--MP3, AAC, AAC+, eAAC+, Real, WAV, WMA, M4A, AMR-WB, True Tones, AMR-NB formats,Visual Radio
>Other Features
WAP 2.0/xHTML,Html;Java Midp 2.0;Push to talk;Video calling and download,Calendar,To-do list;Photo/Video editor;Integrated Hands Free,Compatible with Nokia Wireless Keyboard (sold separately)


Complete Hand 0n Review:
Let me start from the beginning and I am sure that at the end of this review you will have a more precise idea of what Nokia N91 is like and whether it is worth investing the great deal of money it costs.
Design & Looks:
I thought that it would not take me long before I started to feel bored with the bluish glossy plastics on Nokia N91's front panel, but it did not. I must confess that N91 is simply an eye-catching device. People in the city transport media would not turn their eyes from it.Nokia N91 is a serious piece of a phone. It measures 113 x 55 x 22 mm. It makes the N70 model look like a poor relative. When I first had the phone in my hands, it seemed as if its 164 grams made it crane forward a bit. It was a mistake. I managed to make Nokia N91 balance on a single finger placed in the center of the phone body. Apparently, the initial feeling was due to the way I was holding the phone. In other words, I had to learn to hold Nokia N91 like a small baby, underlying its "head" with my pointing finger. A great part of the phone body is made of real steel. Unlike Nokia 8800, N91 is not glossy, but rather matt. It gives the impression of a device of far more value than its forerunners, even if this may be considered extravagant. The rear cover is the biggest metal-made part of the phone. The lock button is located on the right. Press it to remove the entire cover. At one time I forgot about this button and tried to open the phone without its "permission". It opened seamlessly, which is quite bad. Besides, the rear cover shows a slight gap, which is otherwise invisible when you hold the phone in your hand.The left side of the phone features a connector for the USB cable, enclosed in the retail package, and a swing volume control button. The loud speaker grill is just below the volume button. It is a pity that Nokia designers have not mounted another loud speaker on the opposite side of the body. It would have come in handy.
O/S:
Nokia N91 is equipped with Symbian 9.1.Active display has undergone smaller modifications. As usual, here you will find standard details like clock, date, day of the week, operator's logo and two indicators: one for the battery and one for the signal.The four ways of the joystick cannot be assigned a certain function as they are needed in the active stand-by mode. If you deactivate the stand-by mode, Nokia N91 behaves exactly like any other Nokia smartphone: state icons and time and date details are the only ones visible on the display. The main menu is displayed as a matrix of icons. Originally, Nokia smartphones had a matrix of the 3 x 3 type. Later Nokia launched the 3250 model, where icons were distributed in a 4 x 3 matrix. In the case of N91 software designers have decided to go back to the "three times three" model.
Memory Features:Plenty of spaceNokia calls the N91 model a music mobile phone. The combination of 4GB of memory space and smooth running USB support represents a true comfort. I even tested a Motorola miniUSB cable and it worked reliably. When connected to a PC, N91 appears as a new hard disk. From this point on, you simply can start copying your favorite music files. The built-in Hitachi Microdrive disk is very small. It is situated between the camera lens and the battery bed. Its precise dimensions are 32 x 24 mm. It rotates at a speed of 3600 rpm, with an access time of 8 ms. The transfer of a 6 MB music file takes no more than 12 seconds.
Camera:
The name of the "Photo-Video" menu is clear enough. It takes you into the interface of the built-in 2 megapixel camera. Nokia N91 is held vertically, even if it is said to be a photo mobile phone. The speed of the capturing of the first picture is quite high for a smartphone with OS. The speed of picture reading and viewing is a little bit slower, though.The name of the "Photo-Video" menu is clear enough. It takes you into the interface of the built-in 2 megapixel camera. Nokia N91 is held vertically, even if it is said to be a photo mobile phone. The speed of the capturing of the first picture is quite high for a smartphone with OS. The speed of picture reading and viewing is a little bit slower, though. Since Nokia N91 does not focus well in macro mode, closely situated objects look bad. Photos of text located in close and medium-far distance are of particularly poor quality. 20x digital zoom is quite smooth. It is controlled through the joystick. Resulting images are not mere crops. Half-zoom is somewhat helpful, while maximum zoom is absolutely useless. I was very pleased with the high quality of the videos shot with Nokia N91. The phone stores up to 60-minute records in MP4 format with a resolution of 352 x 288 pixels. Video runs smoothly. The microphone captures sound very well. While shooting you can zoom or use all color effects described in the photo camera section of this review. Sound recording can deactivated, if necessary.
Muzik:
Nokia N91 music player is brilliant, except for several insignificant details. ID3 tags are supported, of course. The player allows for creating infinite amount of playlists. Music files are automatically ordered by artist and album name. Music files can be downloaded into the MyMusic folder through a standard "explorer". Every time you run the music player after new data has been downloaded the phone reminds itself that it should browse all available files and order them in a rational way. As expected, Nokia N91 does all this by itself. The time it needs to file new information is proportional to the amount of this information. For example, two albums, each one of 10 songs, take the phone approximately 15 seconds. The work with the player menu is similar to the work with iPod devices. First you enter the album or artist folder, then you open the particular album (N91 counts total time automatically), and finally you get to the individual songs. According to the Nokia official website the search of a particular song takes approximately 12 ms; each additional song needs a mere 1 ms; an entire song is read within 22 ms. In Nokia N91 original package you will find a HS-28 headset (remote control included). But if you are keen on seriously using the phone as a music player, please put the original Nokia headset aside. They are not bad at all, but are still worse compared to the headsets of the Nokia N91 competitors. They are incomparable to the brilliant performance of Sony Ericsson W800 plugs, for example. Sound became even better, when I plugged in the Sennheiser HD 215 headset. I am sure that even editors of audio-tech magazines would have liked it. The Nokia audio technicians have done an excellent job.