A crackle in the stroke...
 

There's a rhythmic (which is to say at relatively the same place in the crank's rotation) crackle, clink, or clank, and in a related story there is a distinct jingle (over bumps). The sounds seem to be emanating from in or around my bottom bracket. My suspicions lead me to believe that my tired bottom bracket is approaching its bitter end. Anyone ever suffer through this most unnerving audible symptom? Thanks...

Can you feel it through the pedals?

Might be that your chain is a little slack. I had this happen earlier tonight. A few clinks and clanks, and also a bit of rattle when I hit bumps and such. I stopped for a second, got off, shook the bike a bit, shuffled the cranks back and forth, and effectively, came to find that a slightly loose chain was the culprit. I probably didn't pull my rear wheel as far back as I could have when I changed the tires the other day. Which reminds me, I'd like to get myself a chain tensioner. Should make my life easier.

Anyways, cool story aside, once again, check your chain.

have you tried tightening your chainring bolts?

do you have metal lace ends? i do and it always freaks me out until i realize i need to tuck in my laces.

if your bottom bracket is dieing you should be able to feel a little play if you wiggle your cranks

try this. I was having noise a little while ago and found a couple of the bolts were loosening up

Hey thanks fellas... I did tighten the chainring bolts and put an agreeable amount of tension in the chain... Shoelace ends have been the culprit more often than i care to admit but sadly, not this time. The hunt continues... thanks again for your time and knowledge... ride on...