It's been a while since I've seen any of the original series, but I was wondering, can other species do the Vulcan nerve pinch? I can only remember seeing Spock doing it successfully. I was thinking I remembered Kirk trying it in an episode or movie but failing for some reason.
Vulcan Nerve pinch Wiki (emphasis mine):
Since Spock, various other characters in the Star Trek spin-offs use the technique, including non-Vulcans. The first non-Vulcan was Khan Noonien Singh, later followed by others such as the android Data, the Changeling Odo, Voyager’s holographic Doctor, and the humans Jean-Luc Picard, Seven of Nine, and Jonathan Archer (though Archer was carrying the katra of the ancient Vulcan Surak at the time).
Some humans, however, have been unable to use the nerve pinch. Spock once commented that he tried but failed to teach it to James T. Kirk. Likewise, when Dr. McCoy was in possession of Spock’s katra, he was unable to use the nerve pinch.
The nerve pinch has been used on Vulcans and the vulcanoid Romulans several times, showing that neither race is immune to the technique.
You can probably explain away most of these examples as non-typical beings (Khan was a super-genius, Odo being Changeling, Doctor was a hologram, Seven was ex-Borg, Data was an android and Archer - as stated - was carrying Surak's katra), that still leaves a perfectly normal human Jean-Luc Picard, who presumably leaned it when he mind-melded with Sarek. (Picard did this in TNG: "Starship Mine" and Star Trek Nemesis). Here's the YouTube clip showing it:- and yes, he's using it on Tim Russ, who played Tuvok in Voyager). Here's the screenshot from "Starship Mine" (from Memory Alpha):
 For some definition of "normal"