Cranbrook is great in nice weather. Lots places to be, um, romantic. You can also go skinny dipping in Jonah on hot summer evenings - just remember where you stash your clothes (don't ask) when the security comes after you.
The museum and Science center are cool. If you go, absolutely hit the Planetarium. They used to do Lazera to Pink Floyd. What an amazing trip. I think they are currently still doing a Beatles Lazera which is also very good. Friday nights, the Observatory is open (check online for times). Go during a full moon - the telescope is more powerfull than Todd's repost mechanism.
Mark
