And I can spend this unit to buy other people's attention. Well, not measured in seconds. 10 seconds of my poorly-compensated time is just not worth as much as 10 seconds of Aaron Spelling's, say. 3 kudos for a personal message to me may merit more attention than 30 for a piece of 'junk mail'. Conversely, if I like an article on stir-fry cookery, I might send a kudo, but I'd send 100 for a good MacareNeXT parody.
Kudos are kool because they monetize gradually.
They are not backed as a reserve currency in any traditional sense, requiring someone to back it with dollars or frequent flier miles. Or an advertising agency can put up an infomercial site and change dollars to kudos by handing out kudos to qualified leads. Kudos are a scenario that motivates a new style of cryptographic micropayment protocol. And the social impact could be enormous. So I think there's good work to be done in this arena.