I added a survey to our wedding website at theknot.com. One of the information links now reads "Cupcake VOTE!" and our guests can click a link to vote for their favorite cupcake/frosting combination.
We have only had about 20 hits on the website this week so it may be less than effective. But, it would be nice to know if one combo is going to be in high demand so I will know to make more of one variety than another.
I think the vanilla/mocha combo is fabulous and the vanilla/peanut butter less so. But what if all out guests love the new Reeses white chocolate peanut butter cups? That's kind of like a vanilla cupcake with peanut butter frosting :)