Portable home bar plans?
A bar is very much like a kitchen island with a seating overhang. There are several sites that either have plans, discussions or links to islands that might suit your purpose.  See, for example:

http://www.diynetwork.com/topics/kitchen-islands/index.html

or

http://www.woodworkersworkshop.com/resources/index.php?cat=673

I made a fixed kitchen island from an unfinished base, a granite top I custom ordered, and brackets I created to match the style of the unfinished cabinet. A shallower version could serve as a classic bar. This is NOT portable (almost no stone top should be). 

You could make it portable by substituting a wooden top covered in metal, a thin butcherblock top, or any other wood or even tile.  Portability could be enhanced by attaching wheels to the base, either caster type or larger wheels with axles, but if you are storing bottles and glasses, you may not want that much movement.