I think we need a thin client on your Google Glass that feeds your personal interactions continuously to an AI engine in the cloud.
Having established that you were the recipient of a well-merited compliment that significantly pleased you, the identity of the complimenter, and the fact that your benefactor is HappyCoin(tm)-enabled, the engine would automatically calculate the exact monetary value of your happiness and create a microtransaction as payment, which you would then hopefully approve while still uplifted.
There's a Bruce Sterling story, "Maneki Neko", that's always fascinated me as model for a potential future. In it, a master computer tells people to perform certain actions it knows will fulfill other people's needs. The more you put in, the more you're eligible to get out. It is, in essence, a gift economy organized by the cloud.
It's the sort of idea that seems tantalizingly plausible with smartphones and the cloud, but is hard to actually put into practice. It's definitely the kind of thing that could drive a host of startup ideas, though.
Having established that you were the recipient of a well-merited compliment that significantly pleased you, the identity of the complimenter, and the fact that your benefactor is HappyCoin(tm)-enabled, the engine would automatically calculate the exact monetary value of your happiness and create a microtransaction as payment, which you would then hopefully approve while still uplifted.