Here are three great free tools to create such visual "social flags" in a matter of minutes:
1) QuotesCover.com – it provides you with tons of ready-made quotes, provers and citations that you can further edit and personalize – it lets you customize fonts, positioning, background image, and throws in some nice touches as "soft-focusing" the background, adding drop-shadows to your text, or emphasizing specific words. Output ready also for status updates, e-cards and prints. Ad-supported. 9/10 – www.quotescover.com
2) ReciteThis.com – it helps you find a relevant quote by providing you with a number of preset genres, it makes it easy to edit it and then it offers a set of 33 pre-designed "visual cards" from which you can pick the one you like best as a support for your selected quote. You can preview the look of any pre-designed card with your quote by simply hovering your mouse on any such card. Ad-free. 7/10 – www.recitethis.com/#
3) Quozio.com – it allows to grab any text from any web page or to type your own quote, before offering a set of 38 predesigned templates that integrate a background photo and a particular font for your text. You can test and preview all available designs and then select the one you like the most. Ad-free. 7/10 – www.quozio.com
To this list I’ll add Live Luve Create, which has quite a lot of sophisticated tools for manipulating the photo and adding borders. Plus, they’ve got a little plugin that works with Chrome (at least) that allows you to instantly annotate a photo from the current page you’re viewing: www.liveluvcreate.com/
And my new favorite place for finding free photos, MorgueFile: www.morguefile.com/
Thanks also to MoreFansForYou for spotting this.