Here's one i found today, it's called JabpLite it's a personal finance manager, i've used eCheckRegister and others that i had to pay for from Handigo and JabpLite is the best plus it's free. The interface is great compaired to eCheckRegister and has alot of features that eCheckRegister didn't that makes it easy to use, such as only allowing numbers in the amount fields on transactions or showing your account balance in realtime. Anyways check it out here:

http://www.freepoc.org/viewapp.php?id=58

To install it go to http://www.freepoc.org/dowload/midp2 from your blackberry browser and download japdlite.jar and let it install it takes a couple minutes but works great on my 7520. Thanks