Coming from the newly dance craze "Jerkin", being "geeked up" either means to be in the hype, getting ready to Jerk, or simply dressing for the part of Jerkin.

first of all, you can get geeked up from many differnt drugs including; meth, cocaine, ecstasy.
the feeling of being geeked up includes; talking rapidly, talking an excessive amount, not feeling the need for food or sleep. usually your senses are stronger, and your heart beats faster. some people may shake, get hot, sweat etc.
here's something most people don't think about when they get geeked up. geek drugs like cocaine, ice, etc. have come downs which is when the drug starts to wear off.
this feeling can make some people want to commit suicide, cry, and sometimes just break down.
if you are suicidal it's not in your best intrest to mess with any sort of drug, besides weed.
the time period that you are geeked up, depends on the drug, meth can last up to about 2 days.
cocaine lasts around 45 minutes.
ecstasy usually lasts anywhere from 3-6 hours. but i have experienced ex pills

Being high on blow, ice or any other amphetamine.

1) When one beats the "cool" out of another.

2) Can be used as a replacement for the term "F**ked Up".

the act of having swagger and steeze, the type of gear you wear when jerkin

To get extremely high on coke, heroine, LSD, molly (MDMA) any drug like that.

High and Drunk and ready for anything. You aint scared a shit when you geeked up.