No Charity is Too Small:

The Messenger of God,Prophet (SAW) said:"If someone gives as charity as little as a single date from honest earnings - and God accepts only honest earnings - God takes it in his Right Hand, then makes it grow for the benifit of the charity-giver, just as one of you raises his foal, until it becomes as big as a mountian.'

(Buhari,Muslim:Abu Hurayrah)