Lists of business plan competitions are widely available on the Net. Next Wave selected two that are likely to be useful to our readers.
The first, entitled The Best Business Plan Competitions, is a fairly good, but edited, list of links to business plan competitions. The second, compiled by the folks at the famous MIT $50k business plan competition, is a good deal more complete, but less up to date.
These two resources combined should put you on your way to finding a business plan competition right for you.