In reply to JackKeen:
I did cold turkey and felt ill, depressed, moody etc etc, it can be worse that stopping smoking if you usually have a fair bit of caffiene. Personally I recommend cutting down slowly.
Tea, green 240 mL (8 U.S. fl oz) 30*mg of caffiene
http://en.wikipedia.org/wiki/Caffeine
What How much caffeine?
Instant coffee 60-100 mg per cup The amount of caffeine depends on how much you put in the cup
Fresh coffee 80-350 mg per cup The amount of caffeine depends on:
the type of beans ('Robusta' contains more caffeine than 'Arabica')
the way the coffee is made how strong the brew is
Decaffeinated coffee 2 - 4 mg per cup The amount of caffeine is usually marked on the packet
Tea 8 - 90 mg per cup Caffeine content depends on how strong the brew is
Cola drinks 35 mg per 250ml serve Cola drinks often contain a lot of sugar too
Cocoa and hot chocolate 10 - 70 mg per cup The amount of caffeine depends on strength of the brew and the other chemicals in the product
Chocolate bars 20 - 60 mg per 200 g bar Chocolate also contains a lot of sugar
Some prescription and over-the-counter medications 20 - 100 mg per dose Some medicines (cough, headache and slimming products) contain caffeine.