One of the first USB stick's I bought for use with my Jogglers has died. It has been in constant use for a couple of years though. Looks like an identical replacement will put me back £8. Certainly cheaper than a new Joggler, had I been using the internal flash and that had gone.
As you've all ways stated, better to use an external flash then the internal ! I wonder how long the internal would have lasted if used in the same way as your USB stick ? Two years of continual use just goes to show how resilient flash can be !
I used my first big flash drive just like a hard drive as I didn't appreciate the limitations of it at the time and it eventually failed on me. When I plugged it in the LED would not light and it was not recognised by Win XP. So I went to a Russian website (see below) and tried a solution from there. It recovered the drive - there are some dodgy sectors on it, and it now has a different name - but better than having a dead stick ! In fact I still regularly use it and it has been fine for 5 years since being reincarnated.