I had no idea, but The Loom mentioned today how Asian clams are capable of male-only reproduction. That is, the sperm is delivered to the female, and it promptly kicks out the female DNA (nuclear DNA). If someone can get a copy of that paper mentioned by Zimmer, send it on.
The trick is that the Asian clams do this with other species females, which solves the initial paradox implicit with this kind of idea. The question is, why hasn't this evolved in a lot of other species. I assume it is because while clonal reproduction is good for getting your genes passed on in the short term, no species with a sufficient genetic complexity can probably survive without sexual reproduction.