Anyone know where I can buy a replacement R4 usb stick?

Mine recently died and I don't know where to look to buy a new one.

In your local phone shop

Just buy any Micro sd chip reader. $7 at Tiger Direct.

mine broke and i got this adapter one from a pound shop for a pound works brill

The one that came with my r4 always over heated after each use until it stopped working.Then it started working again without any problems.