My favorite customization application is called co0kie home tab. there are a number of ways to get it, but the best way to get the most up to date version is through www.xda-developers.com. search for the app, and find the download link on the bottom of the thread.
there are also a number of custom ROMs that you can install on the phone. be careful with these though because you can brick your phone loading these if you aren't careful.
www.xda-developers.com is the best site to go to to find custom apps and fixes to the phone.