Here are a couple of ideas which work to help a group raise funds every day of the year.  In the ideal situation, this could mean thousands of dollars a year:

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1)  Perpetual book sale - ask a local business to place a box of donated books in an area (typically where a hostess is in a restaurant) and a donation jug (water cooler bottle) next to it.  Put a sign on the box or wall (ask them) saying: Hardback books are $1.50, paperbacks are 75 cents.  You will need a steady supply of books (ask the public for donations via free press releases--or whatever means), and you will need to get the money out of this huge container every so often.  This is IDEAL in a tourist location because the customers are everchanging. 

2)  Even $1or $2 will help.  Put this in ALL your advertising--in EVERYTHING you do.  That tells people:  I can make a small donation--and I can send CASH now--immediately!

3) The basic can or box (sometimes have to be bolted down) always works.  You have to work out the details with the stores, but you can buy containers in a dollar store.  I personally donate at least $75-$100 a year this way.

4) Quarterly SUPPLY DRIVE - run free press releases (any way you can--TV, radio, etc.).  Tell the public their animals need supplies and what they are.  Designate a location and drop-off hours (don't forget working people).   If you end up with 200 rolls of paper towels, you need to consider some places to store them.