FYI, root explorer won't work. You can only remove them via adb while mounted in recovery.
How many apps do you have installed? I have 38 apps installed, easily over 1000 texts, and I've never cleared my cache and I'm still at 68mb internally free.
If you search the General MTS forum, there's a good thread in there on what's safe to remove.
MyTouch 3G Slide
SlideMeRoot5 by Eugene_373
Thanks Eugene_373, Wes, Cheifz, htcclay and everyone else for your hard work!
Black HTC G1
Need to upload files? Use it as you please.