Here's a list of over 13000 keyword luv blogs where you can leave a backlink to your site in the comments, including your keyword. This means you will get a do follow link to your site, which will include anchor text. This can really help your backlinking efforts.
I recommend making manual comments. The PR rank is included for each page and there are a number of PR4 and PR3 in there. This list was created Jan 2013 so most sites are current.
