Originally posted by: dflynchimp
Input lag as defined by LCD specs/labels is a marketing tool. LCD's refresh at 60Hz, which means every frame lasts 16.33 milliseconds, so anything with real-world GTG lag of less than that would not be overtly noticeble (it's possible for gamers with fast reactions to notice a little lag, but most of us wouldn't notice it)
The problem is the input lag producers slap onto their monitors are often decieving. Anandtech's 24" LCD roundup actually found some (mostly S-PVI) panels to have as much as 30ms worth of lag. That's nearly two frames worth of lag, which pretty much anyone should be able to pick up. Bottom line is if you're into fast paced gaming you want a TN panel. I got the Samsung 2493HM after reading the aforementioned roundup because it had good pre-calibration color accuracy (for a TN panel) as well as good response time. There are alot of other good 24" displays if you shop around for reviews.