I just bought a very low cost flash shoe adaptor from these guys:
http://www.gadgetinfinity.com/home.php
It cost about $20 plus shipping. That beats the Sony adaptor hands down.
Mostly I wanted a PC contact for studio flash equipment, and I would do my own manual flash settings.
However, I found after trying it, that you have to set the Sony A300 (my body) to "no flash" , either using the Fn button to turn onboard flash OFF, or using the no-flash setting on the quick-dial, to get the PC contact or hotshoe mounted flash to fire.
I think I might buy the Vivitar DF400MZ Flash for Sony / Konica Minolta Cameras TTL (from the same above reseller, in Hong Kong) because it is the only low-cost option I can find that supports ADI, which is the Sony Alpha onboard TTL option. Unlike non-digital TTL flashes, you must have an ADI flash. Besides the wicked overpriced Sony flashes, you can get this vivitar, you can also find a sigma, a metz, and others.
The second best option for me, besides the cheapie Vivitar above with ADI, is the SIGMA EF530DG SONY SUPER FLASH SO-ADI, which seems much cheaper than the Sony branded units.
Warren
Toronto,Canada