MySQL is a great database and it has amazingly good built-in replication which helps for backups, load-balancing, performance and redundancy.
After my post yesterday with my searches in it, I got a couple emails asking how I set up MySQL replication. It's not hard, and there are some great resources out there.
Here are some references to get you started:
Spend a day or two reading those and you'll be able to sprechen MySQL like an expert.