Slow Application Launch - SL

I'm noticing that launching apps on my Macbook is taking a long time, I've reduced the number of apps running in the background to see if it would help but it doesn't seem to improve that much.

What can I do to speed up application launch and the system in general?

I'm using SL 10.6.2

Disk maintanence. Run OnyX and run the automation process.
Also, how much space to you have left on your HD?

I have aprox. 83 GB available from 160 GB. Forgot to mention that I run Bootcamp to use WinXP, I have some Windows only apps that me and my brother use. By disk maintenance you mean repair permissions and stuff?

Yep.... which is where Onyx will come in handy. It will do that as well as clean the caches etc.
It does a great job, and there are many options, but unless you know exactly what you are doing, I would stick with the automation tab.