When a relatively small app is installed (aka dragging to the apps folder) there are usually just two files created.
TheAppsName.app
com.apple.TheAppsname.plist (this is a small file that stores all the app's preferences)
You can spotlight for the plist and the app and just trash both. (If you're on Tiger) If you're not, the .plists are stored here:
MacintoshHD/Users/yourshortname/Library/Preferences/
If you're interested in some shareware that does it all for you, there's a program called "App Zapper". Search for it on
www.macupdate.com. This does the two steps I mentioned for you.
Deleting apps on OSX is totally different from Windows, in that it's easy...