Tasteful 50th Birthday Ideas

Help! I`m planning a surprise 50th for a friend. He is pretty sensitive so I`d rather not do the typical "Over the Hill" black theme. Instead, I`d like to do something more uplifting. I`ve seen many themes for "This is your life" type parties...however the problem is that I don`t know enough about his past to do this kind of party (only been friends for 2 year). Does anyone have any cute ideas? I was thinking to do something like "Hawaii 5-0", but I`m not sure.