Blogger / Blogspot.com using widgets (rather than a classic template - most likely for FTP blogs), you can now display Google ads between your posts.
See the Adsense post which has a helpful step by step howto with pics.
Remember though that "AdSense policies limits you to a total of 3 ad units per page" - but the good news is that Blogger will automatically prevent you from going over this limit. Which is nice.
Digression on backlinksI've actually known for a while that you can show ads between your posts in Blogger, thanks to the ever-vigilant Kirk plus I spotted the new Blogger Help on this, but refrained from posting earlier because I'm being mercenary about Blogger backlinks (Blogger on backlinks).
Did you know that if you publish a post, then later edit your post to add a link to another Blogger blog post, your post will not show up in the list of backlinks for that other Blogger post? It must be something to do with how blog search engines work, or how backlinks work, or both.
Many a time I've beaten Google blogs like Blogger Buzz to the punch and blogged about a new feature of Google or Blogger before it was announced on a Google blog - and my reward is not to have my blog post listed in the Google blog's backlinks.
So, this time, I've waited it out. Maybe sometimes it's better to be first to report on something, but not always... Of course, I bet that now I'm posting this there will be something on Buzz later this week, probably even tomorrow, so I'll still miss out on the backlinks listings somewhere!