US users have 12 promo codes so far for free apps and until this weekend, UK users have had none. This just changed though, with the official HP Palm blog finally listing a somewhat underwhelming 3 free promo codes (separate codes for UK, Ireland and Canada in fact), which will last a limited amount of time because HP have to pay the developers of the apps for every code used. Hence, there is a limit on both the number of times the code can be used across all TouchPad users and also a time limit (16th September 2011).
Needless to say, I didn't post this up until I'd got my three free apps, which are Big Boss (not very good - cartoony punch-up game), Camera for TouchPad (an app that really should have been shipped with the TouchPad in the first place) and Glimpse (a somewhat crowded "multitasking" app that basically puts different types of feeds in a split screen layout - not that essential). Don't delay claiming your codes because I bet they'll run out fast.