Gorgeus shots Jose Luis! Welocme to the forums ;)
Thank you very much, 0eyvind (by the way, your name is?)
You have also a very good galery... I'd like to see some B&W attempt from this one http://www.flickr.com/photos/29788668@N07/2787731884/
I'm more Nikonian than Sonyian... her measurements are apart, despite the recurrent wrong WB issues.
I was a Minolta's enthusiast in the past, on the film era... and with some dimage 7, 7i, and A1 models.
here another technique with good results on fireworks theme.
The use of the bulb function (unfortunately I don't have it on the LX2), actually is a very important feature to shot fireworks.
With a tripod and a remote command, wait until each firework (your main subject) become all expanded.
Right on this precise moment, fire just the most small bulb time you can.
(as the lights are moving much more slowly and the target is to do not blur them as a rainbow)
Repeat the process 6 to 10 times, and see your shot.
(if you put some top of buildings or other subjects bellow your main subject fireworks, you'll see then a good combination night shot with the all main subject filled by many coloured small lights)