- Why would you want to use email? – I'd like to add links by email, so I can add to Delicous an article I am reading offline from my iPhone, in Instapaper or Read It Later.
- On Ping.fm – Ping.fm only provides a partial solution as it, unfortunately, doesn't allow you to set tags.
I tried to see if this was possible myself a while ago but it seems delicious doesn't provide this functionality. There is, however, an iPhone App called "Tasty" that allows you to manage your bookmarks with Delicious. http://tastymobile.com/