Macbook running really really slow...

I have a mbp and am running 10.6.4. and it is running incredibly slow.

Safari runs like I have a dial up connection from the mid 90's.
I have checked my speeds download is 11mbps and up is around 3mbps.

I get the spinning beach ball everytime and I mean everytime I click from one application to another.

When writing text anywhere I have to wait until the text catches up with me, usually after a few seconds of the beach ball

I have 100gb free on hard drive
I have repaired disk utility
I have emptied caches

What else can I do to improve performance?

I have been so disappointed with this mbp, so sticky, so slow, grrrrrr...my previous macs were so much better.

There's not a lot of information there really to judge, but generally sudden slowdowns come from two causes in my experience:

1. Your hard drive is nearly full and/or you have WAY too many applications open at once. A lot of PC switchers don't seem to understand that closing an app window doesn't mean you've quit the app.

2. Your hard drive is starting to die.

The second theory is pretty easy to test: use your external bootable backup (because you DO have one, RIGHT?) and boot from it. Is your Mac zippy and happy again? Well then your boot drive is probably dying.

If you don't have a bootable external clone, I suggest you make one ASAP. I like SuperDuper or Carbon Copy Cloner for this.

Try Oynx or MainMenu and do a deeper clean. Repairing permissions via Disk Utility is ok but it only cleans root level.

With these two Apps they go a lot deeper and do a more thorough job ..... Worth a try

Cheers

could be software corruption. back everything up and uninstall and reinstall OS. try restarting and holding down d as your computer restarts. run a full diagnostic. let me know what your result is.