Always a fan of getting more mileage out of your work, I liked this site that gives you a simple interface to bookmark a site or page onto MANY different social bookmarking sites.

http://www.socialmarker.com/

There's a nice feature that even lets you choose only the ones that don't have "no follow" tags.

I like to grab them all, but that's me.

check out the button's that you can use even to get more mileage from your posts.

Later Addition: Since I made this post, I've found a tool that makes bookmarking on multiple sites a LOT easier.

Have a look at BookMarking Daemon, it'll save you a ton of time and is well worth the low cost of the software.