Try to read the phones' reviews in the links below. Some of the interesting stuff you will see there are...
N9 Key features
Quad-band GSM/GPRS/EDGE support
Penta-band 3G with 14.4 Mbps HSDPA and 5.7 Mbps HSUPA support
3.9" 16M-color AMOLED capacitive touchscreen of 480 x 854 pixel resolution
Scratch resistant Gorilla glass display with anti-glare polarizer
8 megapixel autofocus camera with dual LED flash, 720p@27fps video recording and fast f/2.2 lens
Meego v1.2 Harmattan OS
1GHz Cortex A8 CPU, PowerVR SGX530 GPU, TI OMAP 3630 chipset, 1GB of RAM
Wi-Fi 802.11 b/g/n
Non-painted color polycarbonate unibody, curved screen
GPS receiver with A-GPS support and free lifetime voice-guided navigation
Digital compass
16/64GB on-board storage
Active noise cancellation with a dedicated mic
Built-in accelerometer and proximity sensor
Standard 3.5 mm audio jack
microUSB port
Bluetooth v2.1 with A2DP and EDR
Nice audio reproduction quality
Impressively deep and coherent SNS integration throughout the interface
DivX and Xvid support
Main disadvantages
No Flash support in browser
Limited set of apps
No office document editing
Non-user-replaceable battery
No memory card slot
microSIM card slot
No FM radio
You may not like the interface of the Lumia 800's Windows OS, but simplicity is beauty. The phone runs Windows 7.5 Tango, and it already has multitasking.
The N9 has few apps, but there is a way to allow Android apps to work on it. It is a lengthy process and I do not think you would be able to do it even if I tell you, but it is possible.
I think I would choose the N9.
