Ok, so here is the skinny on the Personalized Key Cards. Yes indeed, the personalized key cards were a HUGE hit! We did NOT put stickers on existing key cards, but I guess that is one way you could do it. I actually ordered them from the company that makes key cards for about 90% of the hotels around the world.
I DID come up with the magnet idea myself ;-) by using business card magnets that you can buy from Office Depot/Staples. I cut them into small squares and put into change envelopes that I then printed and put labels on the envelopes to instruct people what they were to be used for. Remember, the magnets will decode the programming, so keep them seperate from the keys once they're coded.
So here is my big tip...contact PLI (see URL below). They can make them with a picture or they have some generic wedding ones with rings or roses. As you can see, we opted for our own picture and text. The company will work with you to find out if your wedding hotel is one of their clients and then ask you to verify which type of key card system they use. They even sent a sample to the Hyatt in Mexico to test the card, but then we brought them all down with us.
PLI - Event Keycards
As for the matches, someone asked about traveling with them. I traveled with them in my CHECKED luggage. I was not stopped by customs in Cancun. I also shipped a few boxes via FedEx to the hotel in advance with a lot of the bag items (eg. the candles, programs, etc). It was totally worth it not to have to lug a bunch of stuff.