Not seen a thread on this anywhere, but tomshardware has a pretty comprehensive review on widescreen lcds up atm:
http://www.tomshardware.com/2006/01/31/do_you_want_a_16_9_lcd_monitor_now/
theres a page showing the full latency of the dell 2405 as well here:
http://www.tomshardware.com/2006/01/31/do_you_want_a_16_9_lcd_monitor_now/page8.html
which comes in around 20ms average.
http://www.tomshardware.com/2006/01/31/do_you_want_a_16_9_lcd_monitor_now/
theres a page showing the full latency of the dell 2405 as well here:
http://www.tomshardware.com/2006/01/31/do_you_want_a_16_9_lcd_monitor_now/page8.html
which comes in around 20ms average.