Steve Blum, the voice of Spike, is in lots and lots of anime dubs, as well as American cartoons such as Megas XLR and Wolverine and the X-Men. Blum actually used the same voice for an American insurance commercial; which is actually a rather humorous choice when you take into account what Spike's opinions would have been on such a company.
Faye in the dub is voiced by Wendee Lee, who is in damn well everything dubbed. In the original Japanese she is voiced by Megumi Hayashibara, so this show has a lot of this.
Don't forget Gaz, everyone! Yep, Edward is Dib's sister!
And if you watched FLCL before you watched Bebop like I did, you'll find that Eri Ninamori sounds like a very sensible version of Ed.
Electra Ovilo in the English dub of The Movie was voiced by Jennifer Hale, which is interesting since it's the only time that she's dubbed anime. She normally does voices for Western animation and video games.
"Knockin' on Heaven's Door" was originally conceived as elaborating on Spike's backstory as part of the Red Dragon Syndicate. But they determined that one of the defining characteristics of the show was the lack of exposition on backstory, in addition to all of the fan theories surrounding it, and thus they decided on an interquel.
