Thanks, that's what I thought :/ However then I read some product descriptions of some cables on Sparkfun that said even though they were 5V they could be used with 3.3V boards like Lilypad, etc. For example this:

https://www.sparkfun.com/products/9718

So I started to think I might be able to get away with it and the Fio might tolerate 5V. I'm not going to risk it though. I was in a rush, should have read the description more carefully...

So I just ordered an FTDI cable to program my Fio, I realised it's 5V not 3.3V though. I have programmed with a breakout board and a 3.3V FTDI cable but never a 5V FTDI cable - will it be OK?

I understand from data sheet Fio can take 3.35 -12 V input voltage, so does that mean either cable is fine? Anything I should be aware of?

This is the cable:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=130824828209