Business plan competitions offer early business exposure to  VCs, Angels, and other potential investors.  It can also provide exposure for your product, if you are in the early growth stage of your business model.  Exposure is crucial to business success.  Here are a few business plan competitions:

Golden Capital Network hosts a business plan competition
Bang Ventures – hosts its own with winners receiving three months of rent in an incubatorlike environment, complete with technology, accounting and management help.

Also, look at University hosted business plan competitions and local chamber of commerce competitions.  Many University competitions require at least one college student, but that shouldn’t be too hard to find.

More information about the potential perks of winning a competition.