As you know, I'm using a planet (several blogs aggregated to one feed) as a kind of link list for my sidebar. I just bumped harvester to the latest svn, corrected some feed urls and added gulli as another source for the sidebar news (sometimes quite interesting news). Beside I wrote some blog authors to look for their invalid feeds. So you're gonna see some more blogs aggregated again.
The planet uses harvester by astro.

Short tip (although I mentioned this before): You can check if your feed is valid by executing

wget -O - -q http://hboeck.de/feeds/atom10.xml | xmllint --noout -