No - the above solution merely puts multiple file types on a single line in the file select dropdown, whereas what the questioner, and I, and I'm guessing thbousands of others really need is to be able to specify several separate lines - eg. JPG Files (*.jpg), GIF files (*.gif), PNG files (*.png), Other (*.*). This requirement is so basic I am astonished no-one has addressed this. The so-called manual is beyond useless. And where others have asked the question (a French user somewhere, you'll find him in Google) Uploadify don;t even provide a response. I know this is a 'community effort' but frankly I'd rather pay a fee and get a product that does the bleedin' obvious. Or am I missing something?
I think that the problem here is that Flash (which is used for the upload dialog) won't allow more then one. I could be wrong on this since it was a long time since I played around with it though. If you look at other flash uploaders (FancyUpload for example) they have the same limitation.
Edit: Wrong of me, Flash does support multiple types via the FileFilter-class. Strange that no other uploader seems to support this though.