| | Re: difference blackberry 8800 / 8820 / 8830
The 8800 and 8820 are GSM devices; the 8830 a so-called "world phone" with CDMA and GSM. The 8820 has wifi capability. The other two do not. All three have GPS.
These are antiques in the smartphone universe. Memory for the OS and applications is small. If you update to the latest OS you will have to pick and choose the few must have apps to load.
Also, if you don't know, you'll need a specific BlackBerry data plan from your service provider to use the BlackBerry data services and even many aftermarket apps.