OT: Hardware-to-Organism Interfaces (h2oi)

[dmm]

Could use some ideas on the following:

1) What kinds of h2oi might be useful?
Example: electronic to nerve cells

2) What practical uses could be found?
Example: improved artificial limbs

Prefer ideas that are based in reality (no X-men, please) and that would likely be acceptable to people (no Borg, please). But doesn't need to be currently "do-able."

TIA