To the OP....NO! Don't mention a single peep as others have commented on. I know of several friends who did and never got the second offer or interview. It's kind of showboating to the interviewer, not a cool idea.
Go to the second interview and hope for the best they pick up and you can drop the first offer. If it means you need to pack your bags, bring the hubby and or the kids, do it. In this tight economy, you have to do what you have to do for 1-2 years.
You can't pass up the opportunity, that's for sure! It's a sacrifice!
Don't stall the first offer time either, if there's a certain deadline to submit your offer and it exceeds the timing of the 2nd interview/offer, they could change their minds, not so good for you. I know it happened to a friend who wanted to stay in the Bay Area and wished she didn't apply into So CAl, in the end, she had to take the offer in the LA area, but misses her husband daily, but like I said, it's worth the sacrifices. It's a good thing they didn't have kids, but they have a lot of Southwest and Virgin Airlines mileage!
Good luck in the first job offer and the second interview coming up.