1.It can have a better logo
2.The creative Commons licence can be moved to the footer
3.You can change your post title tags
4.You can use Feedburner on your own domain
5.Nofollow all external links (like feed links Creative commons link etc..
5.You can create a feedburner email subscription and put that link in the top right nav for mail(it is not linking anywhere now)
6.You can create a google SMS channel so that users can subscribe to get jokes on their mobiles - Link
7.you can remove the Links to this post links on the home page
Subscribe via RSS doesn't mean that you can get feeds directly to your email So this sentence is irrelevant
Quote:
"Get Jokes directly to your email!"
You can add that if you use feedbuner email subscription..
I see some empty boxes in the side bar - one below the adsense ad and above the twitter link
and 3 empty boxes below the list of friends - It will look better if you remove those
And you can follow some SEO tips
All of these are just suggestions!!