I like my Light & Motion ARC HID and I've got the small Lithium Ion battery. It is _not_ inexpensive but since I commute via my bike and I routinely leave after 7pm it's worth every penny I spent.

The other thing you should consider when looking at lights is not if you can see ok when it's a nice night out, but can you see when the weather is not good, if you ride in such weather. Since I commute via bike, rain or shine, this was very important, especially since I have a little bit of night blindness. The L&M ARC HID fits the bill to a T.

For rear light I use a Cateye TL-1000. It uses 10 superbright LEDs in total, 5 on top and 5 on bottom. Four of these 10 are used to illuminate the side of the light so you end up with six rear facing super bright LEDs, two superbrights on the left and two on the right. Helps cars coming at you from the side see you.

Other lighting that's also on the bike are hokey spokes on the front wheel, for even more side make-the-car-see-you-in-the-darkness-with-colorful-patters lighting.

Mel
(Who's not quite completely gone but has been busy for months do to work)
[HI EVERYONE! ]