Here's an article on these guys: http://wheels.blogs.nytimes.com/2012/03/01/ridepal-to-help-b...
Also, if there's a market, why doesn't someone on YC solve this problem?
The GBus was started as a 20% project by a single engineer. He got a group of fellow coworkers together and charted a van to commute to work.
When I was working in Finance in NYC, a bunch of the traders got together and chartered a van to drive them to the office in Stamford, CT.
It's really not a hard problem to solve.
Edit: Here's another: http://abclocal.go.com/kgo/story?section=news/business&i...
_______________ For employers wishing to reserve a certain number of seats on specific buses at certain times, RidePal plans to sell subscriptions, starting at $250 a month for companies of up to 50 people. That subscription is credited toward fares, which start at $8 a seat for trips within a 10-mile zone and go up to $589 for a monthly pass within the largest travel zone, which extends up to 75 miles from the pickup location. _______________