Lets see...
Cargo community:
Air Cargo Carriers - Shorts
IFL Group - Convair, Lear F.O. etc.
Royal Air Freight - as above.
USA Jet - Falcon 20 F.O
Ameristar - As above
Ameriflight - believe two pilot ops on the EMB120.
Cape Air - Cessna 402. If your close to 1200TT they let u sit as an f.o and log time. Become an employee after that.
Airnet - As above, although not sure if they are hiring these days.
Canyon flying:
Scenic airways -DHC6 Twin otter.
I'm sure there are others. Google is a nice thing as is this.
www.aircharterguide.com -> search by aircraft type or state or whatever.