module rules html email

Rules, quite simply, rules. It's my new favourite module--thanks so much guys!

What I am wondering is, is there any workaround to send HTML emails with Rules. The client has requested this functionality, and I thought I'd check here before saying "not possible". I couldn't find anything about this in the support forums, so I hope I'm not rehashing an existing issue.

I'm fairly familiar with Drupal, but not PHP (yet), though I can modify existing code somewhat.

Thanks in advance.