Mechanics aren't really much of a problem in SA though. It all boils down to the conflict system, so it's just a case of deciding on the skills and capabilities involved then assigning a timescale.

I'm a GURPS fan also, and this thread came from my re-reading the GURPS sourcebooks for Uplift and Alpha Centauri (mentioned above) and realising that with a few additions SA would be a far superior system for running these ultra-tech settings than GURPS. The use of Psionics as a "Vector" for Metatech was based on the "subtle telepathy" model that those settings both seem to use. For other settings, it might be necessary to have a Psitech capability added, which depending on the skills being used can function as Stringtech (pyro/telekinesis) or Nanotech (ESP/Precognition) in tests.

Both settings I mention seem to have machines that can block or enhance psionics, so these things will exist, and higher level effects might require their use. As for a Neural Mesh, that's another GM call, but I'd say it might let someone use Cognitech to defend against Psionic manipulation if the correct lens is installed.

That said, the list of questions is a very good one to give to a GM who's looking to adapt/create a setting with Psionics.

1. What can you do with psionics?
2. What is easy to do? What is difficult?
3. Can psionics be learned? Implanted? Can gene therapy induce them? Must you be born psionic?
4. What is their range?
5. How do they interact with the physical world (e.g. can I build a psi-blocker out of non-living matter)?
6. How do people without psionic powers effectively resist psions? If they can't, it makes a good Capability. If they can, it makes a good adjunct and enhancer for Metatech.
7. What wins out when they conflict - meshes or psionics? Is it a roll or not?
8. Can you control minds? Can you do it undetectably?

I should first state I am well aware that psionics have no place in any attempt to even remotely stick to Hard SF, and no place in the standard SA setting (though I don't consider the SA setting nearly as Hard SF as the author seems to think it is). I was considering adding them to the rules in order to use them in other existing backgrounds which are sufficiently high-tech to warrant using the SA system. The Alpha Centauri computer game is the main one (and given that the various factions have all had write-ups on this site I'm obviously not the only one), with David Brin's Uplift series being another. Both have extremely advanced technology and the existence of psionics.

My own inclination, based on the simplicity approach, is to make psionics a part of Metatech, or even have Psitech replace Metatech entirely. In Alpha Centauri, social engineering is widespread enough for Metatech to play a big part, so I'd have psionics simply act as a "Vector" for Metatech conflicts. Instead of having to speak to implant or modify memes, you simply make contact with the target's mind. In the Uplift books, social engineering is almost entirely absent, but psionic technologies are in widespread use, so I'd have Psitech replace Metatech but use similar rules.

Does anyone have any better ideas, or suggestions on how to improve on this one?