I came across this list of 20 tips for using deli.icio.us to drive traffic to your site, and while it is geared more towards commercial sites, I think there are some interesting ideas for organizations like the ones we work with.
Many of the ideas on the list are generally good ideas, not just for using del.icio.us.
8. Find a niche: By posting content in tags that aren’t wildly overpopulated but still popular (look for second tier terms on the popular cloud to find these terms), it’s easier to get traffic, and even better, targeted visitors that are more likely to bring conversions.
9. Email your post to other bloggers: Seek out other bloggers in your niche and ask them to take a look at your post. Whether they bookmark it for later, or pick it up and share it with their readers, you’re golden either way.
12. Reciprocate: Find pages that link to your site, and bookmark them if they have relevant content. When they do well, so do you.
19. Use catchy titles: Some titles just beg to be bookmarked, like “[Blank] Little Known Ways to [blank]”, and “What Everybody Ought to Know About [blank].” You can find these templates and more at Copyblogger. Often, you’ll get bookmarked even when someone hasn’t read your entire story.
There are other tips that I would ignore completely, or that are not really geared towards organizations (Rather than companies), but regardless, the whole list is worth a quick read.