On the topic of marriage, someone told me that the best advice he'd gotten was to take a prospective partner camping for two weeks. He didn't heed it, and he's still paying for it.
Just think, it you go camping together, you get to see the following.
-Can s/he tolerate inconvenience, or is s/he a pampered brat?
-Can you act as a team?
-Is s/he whiny and complaining?
-Can s/he improvise with few resources?
-Will s/he lose her temper when you spend too much time together?
-Can s/he rough it with a smile?
-Will s/he blame the nearest person (you) when things go wrong?
-Can you still stand each other at the end of the two weeks?
This method doesn't necessarily work in reverse. I've had great camping experiences with two different men. My reaction to the tent collapsing during a huge storm was to laugh and enjoy it. But no one dragged me to the altar. This is not so bad, because I'm not big on marriage and tradition, but I do feel a little cheated that all good camping ever brought me was two trips to the altar... as Best Man.