fella on another forum like the milk jug idea so he filled one with water and went fishing. :rolleyes:
You probably know this but be really careful about anchoring a canoe in current - they don’t act anything like a flat bottom and can flip over in a heart beat if the current is too fast. I use about 9 inched of logging chain. Doesn’t hang up.
I use old window sash weights. They are heavy but will slip a little in current (which is good for safety). They don’t ever get hung up and they cost about $1.00 each.
jed
lots of folks use chains 6" to 12" length, then drag to controll your drift.
A lot of great ideas here. Thanks to all for sharing. I still haven’t quite decided which route I’ll take. I really like the idea of the ankle weights because I seems like they would be quieter. I don’t think they would make as much noise banging against the canoe.
I almost bought a pair, but then I realized that it was $20 for 20lbs of sand in a pouch. I just couldn’t pay $20 for a little sand when my kids would never notice 10-20lbs missing from their sandbox. 
I use a 3lb dumbell. I subscribe to a rule that I was told a few years ago…if the current is too strong for a 3 lb weight to hold you, you have no business anchoring a canoe there. It may be overly cautious, but it keeps me out of trouble.
Instead of tying it off on the canoe or kayak, I clamp the line to the gunwale with a cheap spring clamp. This way I can turn it loose with a quick squeeze or even a backhand slap in an emergency.