I would check it at lest every hour and take it off the charger when its finished light comes on or turns green (however that one works) then if you have a digital multimeter, check the voltage fresh off the charger. If it reads 4.2volts or slightly below, like 4.19 would be better, you are probably ok to use it until you get something better. If it reads much over 4.2 I would either not use it, or check cell voltage before finished light comes on, anything over 4.1V at rest will give you ok runtimes and be safer than overcharging... I have a xtar vp1 that works well, they have a newer vp2 that people seem to like.
I do not charge any li-ion cells overnight. I figure I would rather err on the side of caution than be sorry...
The above mentioned Xtar MC1 looks pretty good for an inexpensive charger. It is better to undercharge a li-ion than overcharge it.. If the wife complains too much tell her it's a safety thing.
At some point soon you will probably want a 3400 mAH cell, I would go for Keeppower, or Orbtronic. There are other good ones but those are the ones I trust right now.
If you haven't already you should read this thread:
http://www.candlepowerforums.com/vb...-Using-Li-ion-cells-in-LED-flashlights-safely