What Twitter app do you have? They should have a "search" function in the menu. Just search using keywords such as your locale, interests, blackberry! etc...
From your PC you can do the same thing once logged onto Twitter. Just click on "Find people" at the top and enter keywords.
View the timelines of the search results and if the people having interseting and informative posts follow them. Then once you have a few of those - check out who they follow.
You can start by adding me if you want - just click on the Twitter link in my sig
David Just give it about a week before you come back and "block" me so you don't hurt my feelings! LOL