Well, it`s hard to give advices to a great blog like yours but...I`ll give it a shot!

First of all...putting a feeds subscribe button is a great idea...first try a big button with same color scheme as your blog. since you don't have a lot of content in your sidebar and you it will go fine with your sponsors images blocks. of course, don't put the button above/bellow these blocks directly!
Placing it under your feeds reader counter will be a great place.
-Using pictures in your posts will be a great idea..(I`ll try it my self in the relaunch after 3 weeks)
Just take a look
here and you`ll understand me. The reason of this..is because that you don't have a header..i.e don't have sufficient # of images in your blog, so adding images will make it more spirited/animated.
-one side note.....I saw that you don't have header i.e you don't use H1 header tag for your blog title...so I thought you are using it in your post titles..but, I`m shocked since I saw that you`re using H3 in your Post title!!
I believe using H1 tag will help you raising ur rankings.
Correct me if I`m wrong.