Try Ace Grinding on Mulberry Street: http://www.acegrindingny.com/
And it's not the same thing, but you could also try an Accusharp 001 knife sharpener (I got mine from Amazon.com) for in between professional sharpening.

Also, Henry Westpfal & Co in Chelsea gets consistently good reviews.

Also Korin: http://bit.ly/aI0BAl

Many butcher shops, including those in independent grocery stores (such as my favorite venue, the late, great Jefferson Market, back in the day) have sharpening services during specified hours, one day a week. Very convenient, plus they really know what they're doing. Sometimes it's posted prominently, other times you have to ask. Something to consider . . . . ;o)

Great. Thank you so much everybody.

I think they do knife sharpening a couple of days a week at Bowery Kitchen Supply at Chelsea Market (9th Ave. betw. 15th and 16th.) Also, a long time ago, I recall having some knives sharpened for my mom at Broadway Panhandler - no idea if they still do it there.

they definetely still sharpen at B'way Panhandler. In Brooklyn we have a wonderful gentleman who drives a green truck around and sharpens knives on the street. There is also a store on Atlantic Ave. called Cook's Companion which does a great sharpening job.