After implementing my del.icio.us RSS feed in both AJAX and Feed2JS, I decided to conduct a little bake-off between the two approaches:
The AJAX version is based on sample client and server code that I downloaded (see Part 1 for references). I cleaned up the code a bit and added simple caching to the PHP-based proxy. Feel free to download the code and give it a try! You'll need a server than can run PHP - it uses CURL to make HTTP requests and it needs to read, write, and delete local cache files. Unzip the files to a directory on your server, change the rss_feed variable in index.html to point to delicious_proxy.php, and you're good to go!
Both approaches are very easy to implement, but with zero technical footprint required, Feed2JS has to win, in terms of simplicity.