I spent some time over the weekend doing some link building work for my sites. It is very time consuming work. ...at least the way I do it. I always find appropriate sites and send a unique email suggesting either a link swap or some kind of partnership. Sometimes people email back very excited to work with me and some folks don't respond (or my email gets lost). I always sign the emails with my first and last name and my city (Boston, MA). A lot of people have lived in Boston as one point in their lives and it is a nice way to connect with folks. (plus I think it helps that I'm female and I live in the US) I kind of enjoy the work ...but as I said ...it is very time consuming.
A new approach I tried was using stumbleupon. I would set it up so that I was subscribed to one niche that I was working on (say it was weddings) then I would stumble through wedding sites until I found an interesting one and send an email for a link.
Still extremely time consuming ...but relaxing and fun work.