Themeing software, the best apparently is StyleXP, though many people here use the PatchXP thinger which patches your uxtheme.dll file and allows you to use non MS themes.
Then you can also use Logon Loader for logon screens
Then I have MicroAngelo for Icon alterations, you can get that from http://www.impactsoft.com/
I use patchxp to hack the uxtheme.dll so i can use non-ms themes. I cant really be bothered fiddling with different programs, when if i change one file, everything can be changed in the same place everytime which is easily accessible