There’€™s a new version (well, that’€™s perhaps a bit of a stretch) of Blogger out and one of the things they’€™ve added is widget-like functionality for adding Adsense to your blog. You need to migrate your Blogger blog to the beta first though, which seems easy enough, and then just follow the directions.
The Inside Adsense blog has it all with screenshots if you don’€™t want to try for yourself.
Thord Daniel Hedengren is a designer, writer, and blogger, and also the former editor of The Blog Herald. He used to be a hotshot in the gaming industry in Sweden, but sold everything and went International. Most recently he wrote a book called Smashing WordPress: Beyond the Blog, and does loads of kickass design.