Just not too short or you'll end up renaming a random variable you didn't mean to... I've heard.

Agreed except for the variables. You can pry the iterators i, j, k, the pointers p and q, and the temporary buffer buf, from my cold, dead hands.

Short variable names increase code clarity, particularly when the functions employing them are concise and named appropriately. There’s not much worse than using something like sourcedata[databufferiterator] instead of src[i]. It reminds me of authors who think that big words make them sound more intelligent. Needing or advocating auto complete in IDEs is a symptom of this kind of code smell, IMO.

Code should be clear and concise; it’s also why I fight for 8 character indentation; if your code is creeping across the screen it’s a damn good indication that the function might be too complex and should be broken up.