You can also use a wash bottle - squeeze the bottle to dispense or add an extra tube and squeeze bulb:
The proper way to do this is a burette:
http://www.amazon.com/Polylab%C2%AE-...ywords=burette (you can probably find it cheaper...try ebay)
Set the burette to drip the stuff into the beaker at the right rate - a drop is around 0.05ml, so 1 ml/minute is a drop every 3 seconds or so. The burette is graduated to allow accurate measurement of the flow rate. The educational supply places sell kits with a stand, burette and burette clamp.
You can make a half-arsed version with a funnel, some plastic tubing and a buldog clamp.
Here's a really cheap way of getting a drip dispense - an IV drip kit: