Not sure how, but I stumbled upon Bookmark Generation a couple of weeks ago. The account creation portion was very impressive. Very fast, and the only thing you have to deal with are the captchas. All other emails (like confirmation emails, etc.) are handled on their servers. This thing works very, very well.

However, when I tried their bookmark posting, I could not get it to work. Also didn't get much support. They did communicated with me, but never really helped me (just a, we'll get back to you, etc.).

However, as good as the Bookmark Generation worked, I am sure they will get the posting part of it working smoothly as well. But, in the meantime, I cancelled my membership and requested a refund, which they have promptly said they would grant me (haven't received it yet, though).