If you highlight that beacon in the center of the map and press ctrl+alt+shift+k, cheats will be enabled.
Once cheats are enabled:
pressing ctrl+alt+shift+ (* on the numpad) gives 1000 minerals to EVERYONE
pressing ctrl+alt+shift+ (/ on the numpad) takes 1000 minerals from EVERYONE
additionally, there's some chat easter-eggs:
"-randomness!" (gives all selected units funny objects for heads)
"-Force Color Red" (Changes the player whose unit you have selected to be the red player)
"-Force Color White"
"-Force Color Blue"
"-Force Color Green"
"-Force Color Pink"
"-Force Color Dark Grey"
"-Force Color Yellow"
additionally, there are some easter-eggs that *don't* require cheat-mode to be on. None of these really affect the gameplay, though some of them were kind of funny:
"-host observer" (If you are host, makes you observer)
"-officialbetatesterreportingin" (you need to have the center beacon selected for this to work)
"-fuglyrequestscrackpacks" (you need to have the center beacon selected for this to work)
"-kewlcrayon13020490" (Changes your color - you need to have the center beacon selected for this to work)
"-Crayon934" (Changes your color)
"-Ash699"
"-kullwarrior568"
"-Ramza717"
"-Cheeshunter674"
"-Sonoma107"
"-Keymasher238"
"-euryleia847"
"-Artyom156"
"-Snigglez434"
"-eluvatar344"
"-Scullhead849"
"-Shyftrider542"