It is useful to create your personal Twitter background since you can show more information about yourself. I have done that, see my Twitter profile.
Here are some useful links with tips and images:
How to Create Twitter Background
Make a Good Impression with a Custom Twitter Background
Free Twitter Backgrounds – I picked one from there.
Twitter homepage design competition closes. More prizes. Great examples!
Make Twitter Your Social Aggregator: Create An Extended Profile
Related posts suggested by system:
Love the first link! Thanks for including in your list and putting this together. A great resource for those looking to customize their twitter account.