FWIW, the NiteRider taillight can only be used in conjunction with a NiteRider battery. Even though it is a nice light, I think it's way overpriced. But that's just my opinion. /ubbthreads/images/graemlins/smile.gif
Felder, are you looking for a front light so people can see you, or do you want something you can actually see things with? For taillights, there are a couple of really good options. I would recommend the following:
Smart 7-LED, sold as the
Planet Bike BRT 1 in the US.
A very good light for city use because it has 7 LED's that point in five different directions for 180° of visibility. Very compact, very durable, reasonable battery life and excellent water-resistance! Steady, flashing and chase light-modes. Uses 2 "AAA" batteries. Comes with two different size mounting brackets (1 normal, 1 small) and rubber spacers so it can fit practically everywhere. FYI, the smaller bracket can be used to mount the light on round edges of most beam mount racks. A light that is comparable to it is the Vistalite Eclipse that Aaron and John mentioned. I personally prefer the Smart because it is brighter in the flash-mode and is more easy to change batteries.
Another good light is the
Cateye LD-600.
It's much brighter then the BRT 1, but it's also much more focused. I think a less then 80° angle at best. Has 5 LED's (each with optical lens) that point straight to the rear (as you can see). It has flashing, steady, side-to-side (ala Knightrider) and random light-modes. Uses 2 "AAA" batteries. I read about water-resistance problems with this light at Mtbreview.com. I haven't had any problems so far myself, perhaps time should tell. Having owned (and still using) several different taillights, I can tell you that this light, along with the Trek Disco Inferno, is one of the brightest stand-alone taillights on the market today. No kidding.
Another very good light is the
Trek Disco Inferno.
The Trek has 5 LED's that point in five directions for 330° of visibility. Of course, between each LED is a 'gap' where there is no direct light, but since the whole light is transparant it has quite some visibility off-axis. Each LED is positioned inside a special lens/reflector that helps cast an output that is just slightly less bright then the Cateye, which is quite a performance considering that the Cateye has all it's LED's pointing straight backwards. So the Cateye is brighter directly on-axis whereas the Trek is generally better visible (thus safer) because it covers a much wider angle. One pushbutton controls slow-flash, fast-flash and steady-beam light-modes, a second pushbutton allows you to choose between 3 LED's or 5 LED's. The mounting bracket looks a bit like the one from the Vistalite Eclipse. It's adjustable so you can mount it on different diameter seatposts and such. Personally, I don't really like it. The adjustable band doesn't seem to mount as tight as those regular one-piece brackets and so doesn't inspire a lot of confidence. Fortunately, you can attach the slide-in bracket to the traditional round one-piece brackets such as those made by Cateye and Smart (Smart lights btw are branded as Planet Bike in the US) if you would like to. There are also some water-resistance problems reported with this light, but I rode in a couple of downfalls and haven't had any problems so far.
These three are superb lights at reasonable prices. Whichever you think suits you best depends on your preferences of brightness vs. visibility. If you have any questions left, feel free to ask me. /ubbthreads/images/graemlins/smile.gif