Lpc2000

> >  Since my device will be eventually powered 
> > from the USB, externally powering the device will only 
> > postpone the issue until later when the code is more complex.
> 
> I find that debugging self-powered devices *much* easier than
> bus-powered devices.  I recommend that you do this.

Agree. Using self power allows you to debug through things better 
because you can handle the connection stuff easier.

Debugging USB is challenging because the timing of the USB protocol 
prevents you from single stepping/breaking.
> 
> > Thanks for the suggestions though.
> 
> Invest in a USB analyzer is another suggestion.  I can't do without
> mine.

What analyser do you use?

Something I have found **very** useful is libusb (Google will find). 
This allows you to do host-side stuff without USB drivers and can make 
for more controlled test apps etc. 

Depending on what you're doing you may never have to write any drivers 
and libusb might be enough for everything.