so i got a new back wheel from my lbs and this morning on my way to work i decided my tires could use a little air. i went to the gas station by my apt and filled up my front tire as usual but when i went to fill the back tire the valve was different then any thing i have seen before. there was no way i could fill it up at the gas station witch was kind of annoying because if i need air somewhere i am pretty much sol. any way here is a picture of what the valve looks like. i think it is called a presta valve but I am not quite. could someone help me get some damn air in my tire, or at least point me in the right direction to learn how to fill this kind of valve up with air.

thanks.

also is there any sort of benefit to this kind of valve. what is the deal with this?