BillyS - 5:57 pm on Jul 30, 2010 (gmt 0)
Here's one that's often ignored:
favicon.ico - Do you have one? How big is the file?
I have a favicon.ico in my browser cache that is 290KB (<-- Not a typo). I have many that are over 30KB in size. What a waste of bandwidth...
Mine is less than 1KB (and so is WebmasterWorld's). The original size of mine was 5KB, it took me 20 minutes find a solution and to fix the file size.