Introductory HPSG?

[Karin Golde]

I've got a colleague who has been doing GBish syntax and semantics for some time, and would like to learn more about HPSG. My understanding is that Bender, Sag, and Wasow (1999) would probably not provide enough depth. He'll read Pollard and Sag (1994), but are there any more recent publications that are geared toward getting the average experienced linguist up to speed?

Thanks,

Karin