A Mr Dwight Williams and a Mr. Ken Lloyd have developed a 1911, Glock and rifle front sight called the DW Battlesight. They claim it allows accurate shooting over 125 yards with a pistol. The sight blade has a hole (well, actually a cone) machined through the middle that in theory allows the shooter to aim more accurately because the target is no longer obscured by the front sight. I was always taught to adjust target sights so that the front blade sat just underneath the target and did not obscure it, so I am not sure how this is better.
The sight can be purchased from DWBattlefield.com for about $59 depending on the configuration.