My dad is retired and he loves to fabricate things. Here is the stump grinder he built. It worked pretty well once we got the rhythm down. Definitely not for commercial use, but it worked great for the two lots he just bought and cleared.
[video=youtube;oodtiFmtg2I]http://www.youtube.com/watch?v=oodtiFmtg2I&feature=youtube_gdata[/video]
[video=youtube;oodtiFmtg2I]http://www.youtube.com/watch?v=oodtiFmtg2I&feature=youtube_gdata[/video]