great list thanks. And no they don't have to be related to your site. The high pr sites help a lot more than most think. Ive done several experiments on article promotion. Where I use a bunch of high pr back links (really like 20) on an article and it will top google and stay for a long time. Try this with 20 low pr backlinks that are niche related and you will not get the same results for the same types of keywords.
Links on websites that are relevant to your niche are going to be worth way more than random links all over the web on "profiles"
Nice list. Thanks for sharing this here. this really helps any niche build up on their SERP provided you are creative and don't overdo it.
Since i am currently doing backlink campaigns for a few of my sites, this will be also included in it Thanks a lot for a great list!