Indeed this is a very cool and attractive way to ask readers to subscribe to your blog by asking them to feed the fish (try clicking the space where they swim) and so they feed on your feedburner. And I have decorated my sidebar with it.
I first discovered it from an entrecard buddy who placed an ad in my blog and also I made a bid on his blog for project wonderful - his site link is - http://www.hulag.blogspot.com/
find out other interesting stuff on his blog.
This fish gadget is available here http://abowman.com/google-modules/fish/#comment-17489
so check it out and enjoy and make use of it.
fun fun gadget...
Subscribe in a reader