Glad to know that I'm not the only "paranoid" person around here. Before leaving on vacation I left an envelope with a friend containing photocopies of my passport (ID page and I551 stamp), Permanent Residency Card, and I-485 approval notice.
When I went home, I had the documents (passport, GC, I485 Approval Notice) placed under lock and key. No need to carry your green card with you (at least in my case since I was visiting parents
Interestingly, I told this to several American friends, and all had good laugh at it. I guess you don't appreciate it unless you're in the situation.
rgds,
sadiq