I am in the same boat right now.
I am ready to give up soda, cause it's bad for my health, and i am pre-diabetic, but i can't stand the taste of tap/faucet water alone, it's just gross to me. and i'm too poor right now to keep buying bottled water. ugh!
my husband has got me hooked on lemon/lime water, just take a fresh lemon or lime and squeeze the juice into cold water and add a little splenda to taste. and i love it!!!
but today i've been naughty and since i didn't bring a lunch to work, i bought a Sprite from the soda machine, i'm usually a Coke fanatic, but that doesn't matter cuz soda is soda.
just try to keep healthy drinks stocked in your fridge all the time, and at work/school keep a couple bottles of water and some packets of crystal light or generic substitute to pour in your water. i don't feel the need to use the entire packet, it's too strong for my taste and it lasts me 2 bottles. i don't even buy soda to keep at home, i just get sucked in when i'm at work and when eating out, and damn that coke machine is like 50 feet from my desk!!!
good luck!