I studied the features of the new version of Blogger, and stumbled upon backlinks. I think the old Blogger had those, but not from the start, and so I never used them. Backlinks basically automatically uses Google Blog Search to find all other blogs linking to an article of mine, and links back to those blogs at the bottom of the comments page. Tell me whether you find that useful!
I also made myself an early christmas present and spent money on the upgraded version of Sitemeter, which gives me access to more detailed statistics. I now get reports about interesting things like what search words my visitors from Google used (current search word on top of the list is "decursive"). And while the free Sitemeter only listed my last 100 visitors, the upgraded version lists the last 4,000, and keeps the overall visit statistics for 6 years, instead of just 1. Nevertheless the upgrade is expensive and not totally necessary, so I wouldn't really recommend it for everybody.