what you are looking for are sightings of the G-man through the game, so far I have seen him 4 times but there may be more since he sneaks off when you get close even if you are not actualy looking the right way (and you still can`t kill him), so I may have missed him in some places, so far I have....
on the tv in the first underground railway lookout post (the one with the vortigaunt and the guy watching tv)
in the concrete canal gullys during the airboat section on a overhead walkway just before the section where you can turn off into a dead end guarded by one CG soldier with some goodies and headcrabs at the end
during the car section where you go from thumper to thumper he can be seen through the binoculars set up by the CG in the second of the houses talking to resistance members in the house where you later fight off the gunship and get the rpg launcher
during follow freeman you can see him on a tv in an abandonded room at the bottom of a stairwell just before it goes off
I think I saw him on another tv in an apartment, but that may have just been a glimpse of Breen making one of his little lectures since I almost missed it, being busy with a couple of zombies at the time.
so who can add to the list?, how many G-man sightings can we get in total?
Mentor.
PC1: P4 3ghz, 1gig mem, 3x160gig hd`s, Radeon 9800pro w cooler (3rd gfx card), 6 way speakers.
PC2: AMD 2ghz, 512mb ram, FX5200 ultra, 16 bit SB.
Mini ATX cases suck.