Manila2D is newer. Looks nicer.
As of right now there are tons of updates since it just came out. Im still using the original one actually and it works fine for what I use it for. I spent some time editting the cab file to include the skins and the xml file I wanted so its just a one cab install for me. That why I havent updated but Im still waiting for the updates to slow down a little then Ill make my cab file that I want.
On the same website as PIMbackup there is a program called DotFred Task Manager. That has a simple yet full featured registry editor. Should be perfect to start out with.
When MrObvious talked about custom roms. There are several custom roms that are put out by people such as no2chem and dcd. There are others but those are the two most known and used ones in my mind. Those for the most part are straight rom installs pretty much same as official rom update methods. If your looking to customize your own rom check out ppckitchen.org. Really easy and to the point will let you pick what programs you want built into your rom. All the newer custom roms that are put out as well as the newer base kits with the ppckitchen are based on the 3.56 rom...just much improved. You havent used a mogul until you use a mogul running nueRom3.
Check out this thread for a start on that.
http://forum.ppcgeeks.com/showthread.php?t=33857
Here is GaMedic's tutorial on using the kitchen
http://forum.ppcgeeks.com/showthread.php?t=33873
Oxios Hibernate is a program that basically releases memory used by programs that have been closed, back to the memory. If that makes sense. You should have that on your phone also.
EDIT: I was just reading your other post and seen that you dont have a data plan.
You must check this out so you dont accidentally use data. This is what I use.
http://www.modaco.com/content/pocket...-free-utility/