Dangerous curves.

I've seen some interesting guitars in museum collections, including the Country Music Hall of Fame in Nashville and the Rock and Roll Hall of Fame in Cleveland, as well as a general instrument collection at the Museum of Fine Arts in Boston that included some early lutes, viheulas and guitars.  One that I'm sorry that I missed is the Museum of Musical Instruments Dangerous Curves guitar exhibit, which toured in 2000-2001.

This link takes you to a slideshow of the featured guitars, and they really got some of the most historically significant guitars together in one place, including an 1830s Stauffer by C.F. Martin's luthiery teacher, the Gibson O Model and guitars belonging to John Lennon and Jimi Hendrix.  On the downside, the scans are of low quality so the sumptuous construction and appointments of some of the instruments are hard to appreciate.  There are a few pieces missing, judging at least by the montage - the Electro String Instrument Corporation's (later Rickenbacker) "Frying Pan" lap steel, the first commercially marketed electric guitar.  Oh, and there's the Log, Les Paul's first experiment in solidbody electric guitar building.  They probably should have had Paul Bigsby's late '40s guitar for Merle Travis as well.

I could probably go on and on, but the montage is a fun five minutes in any case.  For the real, coffee-table format goods, seek out Tom Wheeler's American Guitars.