"More on passive aggressive linking with nofollow" -- Jay Fienberg, via comment on Joi Ito's blog
Interesting what trails lead through blogs sometimes. I found this while reading more about SMS.ac, which it seems you should avoid.
Jay makes some very good points about being precise with the semantics of Google's rel="nofollow" trick. One reason I find this so interesting is that when Google came up with this good idea, a lot of people got a little over-excited and were making noises to the effect of "see, never mind all that semantic metacrap stuff. Uncle Google gives us all the semantics we need". But Jay's note demonstrates that at best what Google gave us is a weak approximation of the sorts of nuance rich linking requires. And the fact that Google had to come up with this trick is evidence that we do need rich linking in the first place. Yes, XLink overdid things with the bewildering array of link annotation options (among other sins), but we can't just overload rel="nofollow" and expect not to be heading into our own hypocritical purgatory of metacrap. At the very least, people should be thinking of what other rel="*" conventions we can settle on in the community.
BTW, Bob DuCharme was one of the few people with sensible commentary when Google debuted rel="nofollow". See "Big week for the a/@rel attribute". But then again, what's new? Bob's the best commentator I know on linking. Full stop.