I've never used a bicycle trailer, but I like the idea, especially for an extended cycling journey. I just saw this neat trailer from Maya Cycle. I really like the way some thought has been put into moving the trailer around when it is not attached to a bike, the wheel barrow concept is very cool.
For convenience when transporting the trailer around, I think the Burley Travoy is also very neat. Its use of a trolley design is exceptional. You can find a nice review of it here.