Hey, the Prince of Cheap here... I had to post this... Ebay seller gadgetinfinity has a great 4 prong hotshoe adaptor!!! search.ebay.com/search/search.dll?from=R40&_trksid=m3... This one has voltage protection so that the flash can be used directly pluged into the adaptor!! meaning it wont require you to buy a wireless trigger to go to it. This one doesnt make the strobe fire continuously when its connected to it! Its voltage protection also prevents your flash from damaging your Alpha! Now if you already have the A700 you already have an available PC sync terminal to use but if you have the A100 you need this! The similar one sold by sony costs about $200!
This one is only $30! I have it and it works just fine! With this adapter you can use any manual hotshoe flash as well as any flash that has a pc sync!
Also, if you cant find it from that link you can type this into the ebay search 4-pin Hot Shoe Adapter for KM Minolta 7D 5D as FS-1100