High-speed point-to-point connection?

Any ideas for a high-speed point-to-point network connection? I need to connect a trailer at a construction site to the main office. Currently the trailer has ADSL and the office has a T-1 and we're using a hardware VPN to connect the two, but the connection is terribly slow. The folks in the trailer need access to a database here.

The trailer is about 50 miles away, so wireless is out of the question.

So far I've been looking at multiple T-1's or even a fractional T-3. Is there anything else I should be looking at, especially something that doesn't cost a small fortune?