"Many people will walk in and out or your life,
but only true friends will leave footprints in your heart"

It is attributed to Eleanor Roosevelt, but I couldn't find conclusive
evidence that proves beyond doubt that this is by Roosevelt. However,
I did find this interesting page:
"A Friend in Deed" or a "Friend, indeed?", StopTheChain,
<http://www.breakthechain.org/exclusives/roosevelt.html>.

On page 32 of his book, "Grandmere: A Personal History of Eleanor
Roosevelt," David Roosevelt states that the poem is "erroneously
attributed" to his grandmother.
http://www.amazon.com/exec/obidos/tg/detail/-/0446527343/

It is my belief that this quote's source is a verse that was printed
on a poster in 1995:

Footprints on the Heart 

Some people come into our lives and quickly go.
Some people move our souls to dance.
They awaken us to new understanding
with the passing whisper of their wisdom. 

Some people make the sky more beautiful to gaze upon.
They stay in our lives for awhile,
leave footprints on our hearts
And we are never, ever the same. 

~From a Poster by Flavia~copyright~1995~

http://www.livejournal.com/users/rainhag/36449.html

The author of the verse above is Flavia Weedn. You can learn more
about Flavia here:

http://www.flavia.com/company/about.cfm?CFID=1649888&CFTOKEN=c2032141a844f086-ABD89D59-BC45-907F-F6DB61E95E0F2AC9&

Note that Flavia's website refers to the "footprints" verse as
"Flavia's most famous quote":

http://www.flavia.com/store/flaviaStore_Main.cfm?CFID=1649888&CFTOKEN=c2032141a844f086-ABD89D59-BC45-907F-F6DB61E95E0F2AC9&action=search&show=all