I use HP monitors all day (and yeah i work for them in Brsitol so this might be biased!!!) however i find they are excellent quality have all the pivot and height adjustments you'd expect from a higher priced monitor and are a fantastic CRT replacement.
I've use a L2045w which is the 20" widescreen on my desk and its amazing performance, the 2065 a more common 20" I also use now the display on that is flawless, no bleeding, excellent contrast and brightness. superb. Also i've been impressed with there 24" guy in the opposit desk has one they look the business.
I've used a range of the smaller 19 - 15inch ones all seem to produce a image on par with my old personal Mitsu Diamond Tron, which i thought would be unbeatable.
At the moment i have a widescreen 19 inch belinea at home and you really can see the quality difference between that budget monitor and the HP ones. Hope this helps
HP monitors are generally pretty good, but they don't get as much notice as Dells or Samsungs. But you need to be more specific about which LCD model you are looking at.
HP and NEC typically use S-IPS panels in their LCD monitors more than any other company to the best of my knowledge. I'm not saying they use S-IPS panels in every single monitor though, just more than others from what I've seen. However, you will never see a 22" LCD monitor made by HP, NEC or any other company since no one (Samsung, AUO, Ch-Mei) makes 22" S-IPS panels.