Wirelessly posted (HTC Diamond: Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 7.11) Sprint MP6950SP)
As far as an app to help clean things out, I recommend CleanRam for reclaiming used ram and ClearTemp for clearing out leftover temp files in storage memory. You can find and download these directly to your device and find many other free apps at www.pocketpcfreeware.mobi
You can also look on here and xda-developers for many many useful items.
Good Luck and Welcome!