Yup, you can buy the 'Subway' unit for around £55 (GBP) which has 2 usb2 compatible ports (no high speed mode too fast for the classic amiga to handle).
Other bits that can be bought are the 'Delfina' sound card, Catweasel which make the amiga compatible with every shape and form of floppy disk ever produced, FastATA for fast IDE ATA ports, Silversurfer/Twister for fast Serial ports.
There is no doubt there are more expansions for it and im sure other amigans will add these.
Isn't there one for fast parallel ports?