Useful links

HTML5 compatibility

http://mobilehtml5.org/

Media Capture

MOBILE / iOS 6+, Android 3.0+, BlackBerry

There is no known solution for Windows Phone at the moment; even Facebook couldn't find one!

http://mobilehtml5.org/ts/?id=23

http://www.raymondcamden.com/index.cfm/2013/5/20/Capturing-camerapicture-data-without-PhoneGap

http://stackoverflow.com/questions/17241707/using-form-input-to-access-camera-and-immediately-upload-photos-using-web-app?lq=1

getUserMedia

DESKTOP / Modern browsers only

http://davidwalsh.name/browser-camera

http://www.html5rocks.com/en/tutorials/getusermedia/intro/?redirect_from_locale=fr

https://developer.mozilla.org/en-US/docs/Web/API/Navigator.getUserMedia

http://stackoverflow.com/questions/21015847/how-to-make-getusermedia-work-on-all-browsers

ScriptCam (paid plugin)

DESKTOP / All browsers

https://www.scriptcam.com/demo_1.cfm

https://www.scriptcam.com/docs.cfm

https://www.scriptcam.com/download.cfm

When everything else fails...

<input type="file" />