My husband got off very lightly but I like to be in control.
The only task I gave him (other than turning up) was the honeymoon and even then I had to stick my nose in. He also came with me to organise the ceremony and the cake. He also wrote the Bidding prayer for our service for his brother to read out.
What about letting him do the cars, mens outfits (just tell him the colour scheme), find ideas for the honeymoon or even arrange it as a surprise - cannot think of anything else that I perhaps would have let my husband loose on!