The del.icio.us social bookmarking service does not offer private messaging between users, but it does offer several features which may be combined to simulate it.
Using for: tagging, I can send one of my bookmarks to another user. However, this bookmark and tag are visible in my public list. By turning on the new, experimental private bookmarks feature (available from the settings page), I can prevent a bookmark from being shared. Combining these two features allows me to send a private message to another user.
I prefer to fill in the URL field with "about:blank", the title field with the subject, the description field with my message, and the tags field with "for:JoeUserName @privatemessage". The next time JoeUserName logs in, there will be a message in the header area stating that there is a new link for them. Upon viewing del.icio.us/for/JoeUserName (only available to the user), my message will appear.
Of course, it isn't quite that simple. Since del.icio.us uses the URL field to index the bookmarks, creating another message with the URL about:blank and for: the same person will update that link (perhaps silently) on the other user's for: page. However, deleting the original message will leave it be on the for: page.
- Delete the message as soon as you've "sent" it.
- Use a random string as the URL
I will investigate these unknowns:
- What happens if I change the for: designation to someone else's account?
- What happens if I delete a message and create a new one with the same URL?
- What happens if I delete a message and create a new one with the same URL and a new for: designation?
- Can I recall messages by modifying them somehow?
- I assume this will work for sending out multiple private messages (like a BCC). Does it?