The FTDI USB/Parallel demo module is featured in this month's Electronics World (formerly Wireless World), with a project to follow next month.

I've just bought one of the modules for GBP23 (drivers are free download), and I'm impressed. The PC sees it as just another COM: port.

Meanwhile, back at the 8052, Triscend have a reference design with USB implemented in the Configurable Logic of an E5.
Unfortunately, they don't (yet?) have on-chip Flash.

PS
There's a mistake in the demo circuit shown in that EW article - let me know if you want details!