I recently discovered a way to bypass the 5mb download limit and download torrents on my blackberry 8800.
Basically it goes like this.
You first must have opera mini installed on the phone. Opera Mini | The most popular mobile phone browser in the world
I noticed with the newer version of opera I can download songs larger than 5mb and that instead of downloads invoking the OEM browser opera downloads the files itself.
Now You need to use the website torrent relay Torrent Relay - Download torrents online (web client)
How it works is you find the torrent you want to download enter the url into the website and it downloads it for you.
After it is done it gives you a link to download the file voila!!
To make things easier you can enter a torrent id from torrentreactor. As far as private trackers I don't think there is a way to use them so you are only limited to open trackers. But hey, torrents on a blackberry and many other smartphones is pretty cool.
I will say this, Most "unlimited" data plans actually have a 2GB/month cap.
The above method can be used on other devices also.