I don't really know much about IM and SEO and only stumbled across this site a couple of weeks ago but I've got an accidental PR3 blog that I exchange blogroll links with pretty much everyone and there are a lot on my homepage. I've got a plugin though that makes the blogroll only come up on the homepage so it's not on every page. My question is, is this harming my PR? Should I only be exchanging links with PR2+ or PR3+ sites or just as many as possible? I've currently got 56 - is that a bit excessive?