John Travolta was in Reservoir Dogs!!!!

Oh well, he almost was...the website NotStarring.com has this to say on the matter:

"
The role of Vic Vega (Mr. Blonde) in Reservoir Dogs was written for John Travolta, but he declined the low budget film. Director Quinten Tarantino then wrote the role of Vinnie in Pulp Fiction with Michael Madsen in mind, but when Madsen was unavailable it went to John Travolta. Thus, Tarantino gave Vincent the same last name as Vic - Vega, making the characters brothers. (A proposed Vega Brothers film featuring the two characters has been discussed but never come to be).
"

An interesting database, searchable by both actor name and movie name.