Spelunking - This word comes from the caving community, the weird guys who like to go down small wet holes at the weekend (fnar, fnar). They may be weird, but their sport is kind of dangerous and possibly exciting. Now the geek community have appropriated the word to describe, er, groping around in new technology or source code. It seems to be a desperate attempt to make IT sound much more interesting than it really is. Look, computing is not cool, get over it.
Grok - What is wrong with 'understand'? It's been in the English language for quite some time and everybody (including normal, non-geek people) knows what it means. Also see above.
Regards - Email and the web have always seemed pretty informal to me. There was a time in about 1990 when I ended emails with some kind of sign off, but now I find my name is plenty to mark the end of a message. So when I see 'regards' (or worse 'kind regards'), I think that the person sending that message has some kind of problem. In fact, I wonder why they are being so formal and wonder if they are implicitly telling me to feck off.
Consumer - Is that all we are good for? Buying more tat to help fuel the economy? I am not a consumer, I am a person. When I think of consumers, I think of Fight Club - "working jobs we hate so we can buy shit we don't need"