I have found great tricks at www.endusersharepoint.com. Here is link that list all of the great posts they have done on this. http://www.endusersharepoint.com/?cat=457
I have also found some great tricks at http://pathtosharepoint.wordpress.com.
My latest find is from http://weblogs.asp.net/jan/. Here he posted a solution for highlighting a row in a list as you mouse over it. I have made only a change to how you reference the JQuery files. Post: http://weblogs.asp.net/jan/archive/2008/11/24/sharepoint-2007-and-jquery-2.aspx
Here is a sample using it on my site: http://www.bitsofsharepoint.com/ExamplePoint/Folderless/Forms/AllItems.aspx
Here is the code:
Upated 2/6/09: I have a newer post that covers more on this: http://www.bitsofsharepoint.com/BlogPoint/Lists/Posts/Post.aspx?ID=26