I'm on the hunt for one myself. I understand you can charge a 26650 in an Xtar WP2 II with a little finagling. There's This on from International Outdoor Store, This from Feilong, This from HKEquipment, Trustfire charger from Manafont. Funny how many sites sell 26650 batteries and lights, but don't have options listed for charging them.
I use my WPII and a dime and nickel between the positive on the charger and the positive on the battery. Works great. Obviously this is a temporary thing, but in a pinch, a WPII and $0.15 is all you need. 
I picked up an Ultrafire WF-188 as a "universal charger". I don't have any 26650's yet, but wanted to be able to charge them as well as 36650's (if I ever get those). Won't charge at a high rate (650mA max).
If you'd get this charger, you'd probably want to follow old4570's "mod" to fix the sliders contacts.
-Garry
I have the Trustfire one. Its called the TR-005 on other sites. I had high hopes for it considering the relatively high claimed charging current, but after some quick tests I never saw over 500mA and once the light went green it was still trickling about 20mA into the cell. I need to test it further but it’s not looking good.
EDIT: the WP2 does work fine I just use a small magnet on the positive end to make contact.
I found another one at International Outdoor Store:
http://www.intl-outdoor.com/16340-to-32650-liion-battery-charger-p-306.html
It's a single bay, but since I only have one 26650 battery, I guess it'll do. Ordering today, hopefully I'll have it inside of a month... My Xtar WP2 II will also work in a pinch.
Hmm. . . only charges at 650mAh. That will be kind of slow. Decent looking charger though. I'm actually sitting here charging my 18650's at 650mAh and wishing it was faster!
-Garry
Imagine 16340 10440 or 14500 at much higher currents than could quickly charge a 26650. The 650mA is an all-around current.
True. Guess I was thinking 26650 size specifically. Wouldn't 650mAh be too high for 14500, let alone 10440? I'm liking the idea of picking up the Xtar WP2 (or perhaps that new Xtar charger just announced for release soon) which allows selection of 500 or 1000mAh.
-Garry
For the 3100mAh, Panasonic recommends a 0.3C charging current.
Most of the chargers are 650mA, but they aren't constant current.
Good charger Garry. I was wondering about the low charge rate (650ma) for 26650 as well. The specs for the Knot Top battery list charge rate as <= 1a. So I guess it's ok to use the Xtar to charge it.
Thanks for the tip, jonhobart! My Knot Top 26650 came today (probably 3 weeks ahead of my new single bay 26650 charger) and the nickel and dime approach worked, but it took a really long time at 1A charge rate. If you have them, 1 or 2 rare earth magnets on top work even better. I don't think nickel is a very good conductor of electricity.
I use the Pila charger for the 26650 battery.
I use the Pila charger for the 26650 battery.
Foy has worked out a 26650 charging scheme . . .
By the way, I bought the TrustFail specifically to charge 26650 batteries and what a piece of junk it is. I still like it however, because it only charges to 4.18 volts. The Solarforce on the left consistantly charges to 4.24.
When charging 14500, Foy struts his engineering prowess thus . . .
uberskilledFoy
Nice "strutting" of skills 
Could you give us your thoughts on the charger?
Looks like you have a lot of money tied up in that charger....
Next order you place with IOS, they have this single bay charger that will handle 26650 for a good price. I have one on order.
http://www.adafruit.com/products/280
Adjustable charge rate of 100-1200ma, full cc/cv control, thermal protection, input voltage of 5-12VDC. This is what I will be using with 26650's, the bigger the cell, the more important to have a safe charge protocol.
Ive got one of these coming for a friend, ill test it out and if it works OK ill give it to him and post my results on BLF
TrustFire Li-ion Battery Charger For 26650/25500/26700/18650/16340 (US Plug)
From a quick bit of research on a few sites it runs on 110 to 240 volt 50 to 60 HZ comes with a USA power cord but the cord is separate from the charger and easily swapped out for an AU or EU cord from a laptop power supply or old printer, DVD or stereo power cord i have a few spares so its not big deal for me and they are cheap.
It will only charge at 1.5 amps so only really only suited for charging big cells like the 26650/25500/26700 batteries and maybe high end 18650,s like redilast, aw's and Panasonic's 3100's as an example. but 1.5 amp is good for a 4000 + mAh 26650 li-ion cell.
Here is how i charge my 26650's with my Icharger 106b+ i can charge 1 through to 6 at a time and i balance charge them like my lipo,s and 18650,s, but i only have 3 x 26650,s right now with more on the way.
DArn it, I have a hyperion EOS0606i that I intend using, however I have no idea how to find the correct pin outs for the balance cable, so I'm stuck charging 1 battery at a time 
Well you will need hyperion balance leads if thats what you intest on doing ? but hyperions leads are rare or not cheap, what i would do is buy one of these
Then just buy the cheap JST-XH balance leads from 2s to 6s depending on how many you want to charge at one time and pick your magnets or battery holders, for 4 or more batteries at one time you want the long leads.
This thread might help if you have not seen it.
Balance charging
https://budgetlightforum.com/t/-/3118
hobby chargers: ive got some pictuers in there of some handy battery holders