You could run a trace through SQL Profiler. Remember this will add overhead to the server, so do not do it on production. It might be easier to break your application into modules and create a trace on each one. Then you would have verification of what is being used. You could then run it through the Index Tuning Wizard to see what it returns.

I have had mixed results with the Tuning Wizard, so do not accept everything at face value.

Bon chance