Must have software?

Hello all I am new to crackberry but I am very interested in becoming part of the crackhead community! Anyways I was wondering if there are any PIM(personal information management) programs out there for free that are for the bb curve with OS 4.5 . I am currently using e-mobile today and is this a program that I use to replace my current home screen and basically keep it open all the time, or is it a program that I just open once in a while to organize things. I mean is it meant to replace my theme/homescreen, or will it drain my battery?