One quick simple thing you can do is turn off animations.

Menu-settings-display-turn off animations.

This will make run phone run a lot smoother and faster

 

Make sure you're using Launcher Pro or some other type like zeam etc.
The Twiz launcher is quite crappy and not as versatile as other versions. Most people go with Launcher Pro. I even paid for the custom widgets deal. I also put the little orange Zeam android in my dock so I can switch to another desktop and have access to a crap ton more apps without having to scroll over 8 screens.

Also use folders. I keep all my games in one folder on my home screen. SOOO convenient and saves a lot of space.

 

You may want to start reading about custom ROMS. Check out this site and start digging around

Vibrant Android Development - xda-developers

I run Fusion 1.1 with Core and its overclocked to 1200.

Enjoy your reading there is TON of information to sift through. Welcome aboard