I disagree with all the people pushing newbies to "just root", "lag fix", "overclock", etc.
These are advanced topics, with significant risk and plenty of ramifications even when they install ok. You'll noticed no one who suggested it to you mentioned any of them... and all of them "break" the normal behavior of the device and make it work in ways that it wasn't designed to. This can cause unpredictable issues... proven with today's first Captivate update (which failed for most people with lag fixes and rooted phones). Best not to dive into stuff like that until you've educated yourself enough about the pros and cons and are willing to take on the risk.
The best advice is to try out a different launcher, such as LauncherPro.
This gives you some really nice extra functionality without doing anything unnatural. Then go and explore all the tons of cool software out there to see what might interest you.