Here are some couple of logos that may come handy when you need them. Bookmark this page if you like because sometimes things become rather hard to find.
CSS3 SVG Logo
HTML5 SVG logo
Share around so that others can benefit too.
You can easily save them as JPG or PNG using a graphic tool such as inkscape. If you don’t know how to do it let me know and I would gladly help.
By the way try imgcake.com as well if you are interested in taking website screenshot. Its a free tool from me and I hope that you will like it.