Cell Phones and Student Passes?

[Columbia]

I don't have a cellphone, so don't expect me to sound all smart about 'em. I have no idea how they work, even here in humble North America. But I don't get it, you go overseas and can you bring your cell? Will it even work there (I mean, if your partner brings one too)? Cause that'd be pretty handy...
Aaaaand stundent passes. For plane ticket discounts, do you actually have to be enrolled in school to get em, or can you just be graduated and planning to go to Univ. *Sigh* I think I know the answer to that...AHH I NEED MONEY! Maybe I'll take a boat. Some fishing boat or sumthin. Yea good plan