What kind of data usage can I use on BlackBerry with just a generic data plan?
You can use third-party software such as Opera Mini, IM+, GMAIL Mobile, Google Maps Mobile, BBWeather, etc. A lot of these applications are free. You just can’t use BlackBerry-RIM-branded applications, but almost everything else you download off the Net into your BlackBerry works. Everything else you would normally use, such as phone, voicemail, PIM, SMS, etc, work perfectly on a BlackBerry.