I'm not sure if anyone else is doing this but I am sending my bridesmaids a card with a luggage tag and now I found these passport covers on Amazon. It just so happens that they all love red so it works for me but the are 2.99 so I just had to post them.
Then, I found these for 10.70 each. I think it's pretty cool and so I am considering these so that they can keep all of there travel documents in one place.
The thing I LOVE about the 10.70 one is that it has a separate passport holder and a pen holder. Every time I leave the country I forget that I am going to need a pen on the plane to fill out my customs forms and I never put one in my travel purse.