The list above is just a dump from my Excel spreadsheet that has the following columns:

Card name
Bonus offered
Date applied
Date activated
Spend amount required for bonus
Date spent
Amount spent
Date paid off
Bonus received
Date canceled
Offer source (web site, mail, etc.)

I'm also careful to record any kind of bonus offer # or print a pdf of the web site as when it comes time to get the miles the original offer is often gone. I should probably add columns for initial credit limit and revised limit, but I'm pretty good about reducing the limit (usually from $15,000 to $5000 or less) when I activate the cards.

I also keep a Quicken file for each card so I know what's outstanding and rarely have more than one personal and one business card in my wallet to avoid confusion, though if I'm working an AMEX card I'll have a MC/VISA as well as AMEX is more difficult to use.

I've discovered that most merchants are happy to split charges on as many cards as you want. I (my wife) recently bought a lot of furniture that took 10 weeks from the time of order to delivery. After paying the initial deposit, I called back every couple of weeks with a new card and charged an additional $750. I'm doing the same for a vacation next February.

As for the FICO score, I've never checked, though the credit limits my wife and I are being offered haven't gone down over time. I guess if I start getting rejected I'll look into the FICO scores for a reason.