Boston Angel Bootcamp was well worth the time to attend.
Sim Simeonov presented an analysis of angel investment outcomes. The net is that most angels lose money but a small number do very well. The difference between losers and winners seems to be that winners make a lot of investments; ie portfolio theory applies to angel investments too. In addition, he recommended that in order to improve deal flow, an angel should get a reputation for making fast decisions and should be able to drag additional investors along for the ride. I'm sure I'm misrepresenting a lot this, so I'll be waiting for Sim's blog post where he explains it in more detail.
There was also an interesting discussion of the problems with convertible notes. John Landry of Lead Dog Ventures said that there is a chance that followon investors would not honor the conversion discounts (which prompted audience comment that it was the entrepreneur's responsibility to protect current investors in subsequent rounds) and that the typical 20% conversion discount is inadequate compensation if the note is held for more than a year with no conversion. John says angels should do the work to put a valuation on the company and should take founders shares. John also advocates taking a board seat and being very active with one's investments.
Recorded video of the sessions: http://www.ustream.tv/channel/angelbootcamp
Slides for additional presentations from the #angelbootcamp twitter stream:
David Cancel - http://talks.davidcancel.com/slideshare/
Alexis Ohanian - http://www.slideshare.net/kn0thing/alexis-ohanian-at-angel-bootcamp-boston-june-01-2010
Also: Good summary at xconomy: