It's unclear from your post what you're looking for.
First, what PDA do you have? That is a huge factor in what options are available.
Second, what is it that you need to wirelessly enable? Is it your PDA, your PC, or both? You need a wireless router and a WiFi card for your PDA to make this happen. What do you have already?
Finally, there's no such thing as a really small portable device that connects to any PC to enable it to give of a wireless connection. There's such a thing for PDAs, as there is for the DS. The assumption is that a wireless setup is already present to connect to.
Give a should back with the info and clarification.
I noticed the Nintendo DS has a really small portable USB device that you could connect to any pc and uses WiFi to connect Nintendo DS to the internet to play game over the net and I was wondering is there anything like that I could get to connect my pocket pc to the internet so I could surf the net on my pocket pc. I doesn't matter if its WiFi or Bluetooth because I'am planning to get new pocket pc. Does anyone know of a really small portable device that could you could to any pc to surf the net on a pocket pc? Thanks for any suggestions.