Chris,
Not sure how you think you have a 50/50 chance of ending up using the same key! you have to type the key in so it's pretty obvious if you type the same one in twice!
All I said is the CDs are generic, they are not linked to a key at all, apart from for the version of office (so any office 2007 home and business key will activate any office 2007 home and business CD)
Not sure why galeck is going on about Belarc Advisor either, seeing as you already have the keys... just install office and type one key in on one machine and the other key on the second machine, and it will activate over the internet, no need to call microsoft.