http://www.flashzebra.com/products/0141/index.shtml I use these. As well there are other options, but I do not think there is any OEM alternative. The Minolta FS1200 would still need another adapter.
As for Sony cameras with live view, and this may apply to other live view cameras as well, if there is no dedicated flash on camera, the screen will show more or less what the image will look like at those settings. Outside, not typically a problem. Inside at ISO 100, 1/200, f/11, the image will be very dark with no flash, resulting in a live view that is very dark because the camera does not know it is connected to a manual flash. Therefore, using liveview, you cannot see what is happening. Some live view models may have an option for "auto gain" or some similar name which artifically brightens the image, i.e. not representative of what the pix will look like with no flash. I do not know which cameras do or do not have auto gain capabilities, except the A33, A55, and A300 do not as far as I can tell. This is only a real problem with the A33 and A55 since they are live view all the time, other cameras have optical view finders. Hopefully the A77 will have auto gain.