If you're in the EU and you want to protest Steam's no-resale policy, just list your Steam game for sale and then email Valve to ask them how you will be able to transfer the game when your auction ends. Here's Valve's email form http://www.valvesoftware.com/email.php I'm turning off the fees on my site for a month starting today - so, no, I'm not scamming you for a percentage of the sale.
Valve will probably tell you reselling games is against their user agreement. Tell them that that's against EU law and mention the UsedSoft v Oracle ruling. If we can get Valve to allow reselling games in the EU, they might allow reselling games all over the world.
UsedSoft v Oracle info: http://www.forbes.com/sites/raywang/2012/07/04/news-analysis-usedsoft-vs-oracle-ruling-opens-up-monopolistic-practices-by-software-vendors/
TL;DR - Protest Steam's illegal no resale policy by listing your used Steam games for sale on www.halfpricedigital.com if you're an EU citizen.