SA4QE has been going since 2002 and in that time hundreds of quotes have been left in big cities and small towns alike across 14 countries. Some 350 of these quotes are recorded here on the SA4QE website, where they can be browsed by book title, contributor, year, location and media.
Russell Hoban was born in Pennsylvania in 1925 and has lived in London since 1969. His 85th year will see the publication by "Harry Potter publisher" Bloomsbury of his new novel Angelica Lost and Found, and he has also recently submitted a new young-adult novel called Soonchild which is due out from Walker Books in 2011.
Chances are you will have come across one of Hoban's books somewhere on your travels, whether it be the 1980 dystopian classic Riddley Walker - with which Cormac McCarthy's recent bestseller The Road is often compared - or the Frances the Badger books which you might have read to your child, or had read to you. In between, Hoban has written scores of books for adults and children alike, and they're all eminently quotable.
Here's a list of things you can do to celebrate Russell Hoban's birthday this coming 4th February:
* Write your quote on a sheet of yellow paper and leave it in a place of your choice - cafe table, bookshop, park bench, telephone booth, train station, you name it!
* Submit your quote to the SA4QE website and it'll be added here by the webmaster with a page all your own.
* Take a photo of your quote in situ and upload it to Flickr with the tag sa4qe and it'll appear automatically in the slideshow.
* Tweet your quote using the hashtag #sa4qe - this will make your tweet appear automatically in the sidebar of this website. If 140 characters isn't enough space for your quote, try www.twitlonger.com which allows you to write as much as you like and auto-tweets a truncated version. (You can also follow SA4QE on Twitter - everything posted to the site on 4th February will be tweeted as it happens.)
* Post your quote on your own website or blog - if you include the keywords sa4qe and/or Russell Hoban it too will automatically appear in the blog feed in the sidebar.
* Use your quote as your Facebook status update for the day. (There are also Russell Hoban and SA4QE groups you can join on Facebook.)
* Use your quote as your email signature for the day, or otherwise drop quotes into emails, text messages and online chats.
* Film yourself reading your quote and upload it to YouTube with the tags Russell Hoban and/or sa4qe and it will appear in the sidebar.
These are just some of the ways you can take part, but the sky's the limit, the world's your oyster and Bob's your uncle. If you have any further suggestions, or are planning any activity in particular, please share it by commenting using the form below.