Want to easily post things you read in Bloglines to del.icio.us? Follow these steps:

• If you haven't already, install the excellent greasemonkey Firefox extension.
• Open up this user script (in Firefox).
• From the "Tools" menu, select "Install User Script.." and confirm all of the various prompts
• Go to your Bloglines account.
• Observe that all "Clip/Blog this" links at the bottom of each entry have been changed to "Post to del.icio.us."
• Click on one to post that item to del.icio.us (you will be prompted for your username the first time you do this).

As an added bonus, the script makes the "Extras" section in the sidebar toggleable, so that it doesn't always take up so much room. This is all done in a very straightforward manner using DOM operations. It is possible that things could be made more elegant with some XPath-Fu. Things may stop working if Bloglines alters their markup significantly.

I would like to integrate the two services even further, but I'm not sure how much more can be done. Ideally each item in Bloglines would have the tags you've assigned it and perhaps the top N community tags as well. However, given the limitations imposed by the JavaScript security model, I'm not sure how to talk to del.icio.us directly, since the scripts will execute within the Bloglines context. In any case, this JavaScript del.icio.us API looks promising.