I own a P900, bought in 2004 in the UK. Overall, its a nice phone, and doubles up as a PDA (partly) as well. I added a 64 MB sony memory card (duo) to it (about Rs. 2000 then) for more memory storage.
The display is a clear and bright LCD screen, that is very visible even on a sunny day. The colours are good, and the phone has a tabbed interface giving you easy access to Messaging (SMS etc), Contacts, Calender, and the Internet. The phone is fairly light, and easy to carry around, but be careful of dropping it - the sides of hte screen are flimsy plastic and chip off easily. But luckily that doesnt affect the phone. I did manage to injure the plug in "headset" part of the phone after dropping it but then I bought a bluetooth headset which has worked quite well since.
The ability to draw and write notes (both) is a very good and handy feature. I even stored some to do lists as notes, plus random phone numbers I didnt want to store as contacts. For each contact, you can store a photograph as well (and the persons photo appears when they call you, or if you call them). You can also store notes - I have so many people with the same name that I need notes to remember which one is who!
I also like the connectivity features - the phone has GPRS, Infrared and bluetooth, plus an additional neat USB connector for synching to a PC. The PC sync works with outlook and I was able to back up everything (nearly). Plus, contacts can be stored in categories. The downside is that for some contacts it will not store additional informaiton in outlook - for instance, some of my contacts had multiple mobile phone numbers, but the sync only stored the first one. Also categories dont get stored in outlook.
The phones adapter is a lifesaver - it works with both 110Volts and 220 Volts, meaning I dont need an extra adapter to carry around when I travel. The battery has lasted me well, and comes through even now for two days without recharging.
The alarm is very unreliable. I have stopped using it now because it rings some days and doesnt on other days, with no different configuration. But the upside is that you can have upto THREE different alarms at the same time, and each "task" or calender entry can also have an alarm. Funny thing is, the calender and task entries give alarms consistently and reliably!
The voice quality is great. Speakerphone is pretty good too, but sometimes has an echo effect especially when used inside a car.
SMS is very nice. If you open the flip, you can use the stylus to input (but no T9 dictionary facility). The input is fairly simple to learn (but different from a Palm!) You have to struggle with "i" and "t" though. The screen gets scratched too fast- I already have two rough surfaces on the screen. You can also close the flip and use the keypad, with T9 dictionary, to input data. One pain point is that if you start writing an sms on the keypad, and then open the flip, you cant close the flip to use the key pad again - you HAVE TO use the stylus. Not good for one hand operation (like in a car!)
You can use external applications written in Symbian. I was able to upload games and utilities bought from the Internet.
Other notes:
1) You cannot shut down a program - once started it stays in memory until you reboot. The memory taken is also quite high! I had to download a program called "SMAN" and use it to constantly flush out memory taken by infrequently used programs. The phone can get very unresponsive!
2) The keys are sticky, and sometimes if you "click" without seeing it might not have clicked right.
3) The phone has support for mp3 ringtones and even playback. I used it as a music player for a while!
4) The camera is nice but is only 640x480, the pictures and video are very grainy on a computer. ALso video doesnt record much.
5) Audio recording is a neat feature but stores only short clips.
6) You can open Word and Excel files also.
This phone has perhaps been eclipsed by other newer models (with megapixel cameras, wireless internet, EDGE etc) but its still a pretty good phone and the battery is awesome. Hope you liked the review!