Oh, here's MTBR's excellent bike lights shootout:
http://reviews.mtbr.com/blog/category/lights-shootout/
The photos of relative beam performance are very illuminating.
http://www.mtbr.com/beamcomparisoncrx.aspx
This is their take on the Magicshine MJ-808:
http://reviews.mtbr.com/blog/magicshine-mj-808/
If any of you have seen my "portable sun" flashlights, this unit uses
the same Seoul P7 LED as my flashlights, but in a bike-specific
package, and with a 3-hour battery pack. The same basic package is
available in a large number of variants, and with VARYING build
qualities. Dealextreme.com alone appears to sell about 4 different
variants of the same basic combo of a P7 emitter and a 4-cell Li
battery pack.
$85, and it really is amazing. You basically buy one of these and risk
getting a bad one, or buy a $400 light set to get the same quantity of
light.
Oh, and now there's this...
http://www.dealextreme.com/details.dx/sku.36018
Same basic unit, plus two auxiliary wide-spread LEDs.
My flashlight lights are exactly that: small flashlights with a single
rechargeable 18650 Li battery (18650 is a standard Li battery size;
it's longer and fatter than an AA battery, but not nearly as fat as a
C cell). Its runtime is about 45-60 minutes on full power, which I
rarely use on the road. The lo-power mode is enough except for trails.
Claimed lumens for such lights are "900," but real-world estimates are
more like 400-600.