I'd be perfectly happy - so long as you disclosed it up front - for ou to automatically add your own affiliate code to links like that where you can (perhaps with special handling for people who post links with their own affiliate tracking already). If you managed "the community" right, you MIT even be able to start a culture of recommending vendors for which the site has affiliate deals - so users might selectively choose to recommend Sparkfun or Adafruit (where you've got affiliate relationships) over deal extreme or eBay (where you don't)
