In order to help thank your volunteers, I found 3 sites you can use to send them thank you ecards. All you have to do is tell them the person’s name and e-mail address where you’d like to send the card and they’ll do the rest. A little thanks goes a long way. 

Here’s the best site I found:

http://www.kisseo.com/ecard/thank-you

This one has more animation:

http://ecards.hallmarkcards.com.au/ecards/thank-you

This one has a lot of options, including animation:

http://www.123greetings.com/thank_you/everyday/