USB2.0 PCI hardware card... worth it???

Might be a stupid question, but here I go.

It's a well known fact that USB 2.0 never reach the 60MB/s that it should on paper. I've read that it's because of the "translation" of data that the cpu has to go through before it's available to the rest of the system.

Anyway. Is there any "hardware" PCI (or PCIe) USB 2.0 card available? If so, is there any performances gains to get from it?

My WD MyBook USB2.0 HDD, 250GB, does 25 or 30MB/s (depending if I test with HD Tune or HD Tach) and stays like that for the whole lengh of the test. That tells me that it's limited by the interface itself. If such a card at 20-40$ can bring it up to 40MB/s (or more), that'd be great! It's the same with my 2.5 inches, 80GB, 5400rpm HP drive. The only difference with this one is that it start slowing down up to 15-17MB/s at about 50-60GB, near the inside tracks I suppose. (I do use this one on the road mostly since there is no power cord to carry)

Thanks for answering my "newb" question.