Examples of clean, legible fonts with download links
350designs.com
350designs.com
Using tools like FLIR (AJAX-driven server-side image generation) [http://facelift.mawhorter.net/] bite into legal grey area. If done right, it won't expose the font file or curves, but that's still contentious.
The SIFr implementation does work to address legalities as well as FLIR. I haven't kept up on it, so I can't speak definitives.