Best thing I can think of is take your laptop and use a 3G wifi dongle or get an IPhone/IPad with a 3G connection...
It all depends on how desprite you are and how much time you wanna spend...
if its only 20 mins a day of something could you buy a plus pack through you service provider for your mobile phone...
I dont think you could use the work computer, IT administrators usually put strict user rules on work/school/libary computers ect.. The IT administrator may be able to come up with an agreement but dont abuse him :S... It may just get you fired!
I do suggest a 3G Iphone as number 1... but then you think about the $'s
well good luck