If you are looking for a good cheap light, try this flashlight--Smartfire V-68C. It uses a Cree Q5 LED emitter, runs on one 18650 battery. On the light is prtd--3.7V Lumens 150.  This is not a huge light, only an inch across by 6-1/4 lenth. The lense is approx 1-3/4 across.  This is one bright light!  I can see my neighbors barn with it--at least 150 yards away. Strong center beam, decent amount of "splash".  Using on a road bike now for neighborhood rides, don't know how it would hold up to mtn.biking, but seems sturdy. The best part is, the light, battery, recharger, and mount came to around $43 from DealExtreme.  Not bad for a great light for night riding.