
We all drink something with our meals, or between meals, or all day long...
There are lots of traditional options:
Milk - Fine when you are a kid and not dairy intolerant. Cost is $0.31 for a 12 oz serving.
Juice - Good once a day and at 8 oz or less, otherwise, the prune juice effect happens! Treetop Apple Juice for Walmart (Seattle area) is $2 / 64 oz or $0.38 / serving. It's also loaded with vitamins.
Canned Sodas - Phosphoric acid rots your teeth and the sugar causes high - low swings. They are often on sale for $3 / 12 pack ($0.25 each).
Enter Modern Times:
Lattes - There's that milk again and at $4 each, they'll break the bank account.
Energy Drinks - Jolt Cola started all this. Loaded with sugar and caffeine and overpriced - boy was it good! Expect wild swings in energy and higher dental bills and more fights with your boss (OK, maybe that's just me). Cost is $1 - $2 each - ouch!
Clear Diet Sodas - Started life as mildly fruit flavored bottled water and are now often carbonated, artificially sweetened in clear bottles. You might as well be drinking diet 7-Up. At least they can be relatively cheap though at ~ $0.47 / bottle. You can often get canned soda still for $0.25 a can.
Bottled Teas - Snapple put this one on the map. Meanwhile a plethora of specialty Green Tea drinks from as many companies as there are Energy Drink makers now litter the landscape. I tried them all and still like Snapple diet Lemon Tea best at $0.83 / 16 oz bottle. Second choice is Lipton diet Lemon Tea at $0.75 / 16 oz bottle. Tea has two advantages - it provides a slowly replenishing caffeine fix, so you don't have the shakes followed by the crash with coffee. It also has antioxidants - good to prevent cancer. Tea is also inherently cheap (despite the bottled tea prices).

My $0.12 Solution - Teabags cost $0.01 each. Yes, that's right - a penny. At Walmart the National brand, tagless teabags are 100 for $1. If you steep it long enough (5 minutes), it makes 1 each 16 oz serving. Sweeten it with $0.05 worth of sugar or artificial sweetener per serving. I use ten tea bags and 10 artificial sweetener packets when I make two pitchers. A 32 oz bottle of Walmart Great Value lemon juice is $1.92. Use $0.06 worth in you want diet lemon ice tea. I use a big old stew pot and make two pitchers at a time. I try to keep three in the refrigerator so there is always a cold pitcher as the next two are cooling off, which seems to take 6-8 hours. For portability, get some standard carry around water bottles and reuse them. Wide-mouthed ones will be far easier to wash.
Savings per Month:
Between the two of us here, we drink 5 servings per day. We did drink one diet Pepsi, Two Snapples, one diet Lipton Tea and one Safeway diet clear soda each day. Cost was $3.13 / day or $93.90 / mo.
Now it is 5 x $0.12 or $0.60 / day or $18 / mo. Total savings per month is $75.90 / mo.
Wow.