OK, so you've forgotten to post that all-important birthday/valentine/christmas card and you're sweating blood.....all is not lost, try out Delivr....it's better than nothing!
"Delivr might just be the biggest greeting card site on the internet with over 3,000,000 images* to choose from. If you want something a bit more unique than your average animated clip art then browse all the images on Delivr and create your own personalized greeting card."
There's others, though I can't remember where I got this stolen (valentinesdaycentric) list.....whoever you are, I'm really sorry and I promise I'll try harder in the future!!
Rattlebox - Rattlebox is really very good. They have great designs, the interface is nicely designed and the themes themselves are actually decent. You can can change all or some of the text to customize the card, and embed video cards on social networking sites, blogs, etc.
Hipster cards - another witty, well designed e-card site that you would actually want to use. Please note there are some off color options so we're going to note it as - NSFW.
Someecards - their tag line is "when you care enough to hit send." These cards are pen and ink and have funny one liners.
MushyGushy - card site where you can upload you head shot into different animated themes (think JibJab) customize, and send.
Smilebox - site where you choose from various multimedia designs and personalize with photos, video, music, words, and style and share via email, blog, or print. (my note.....requires download)
meish.org - for the anti-valentine crowd. If you hate satin bears and VD (my note....assume they mean Valentines Day!) makes you want to hurl, these non-sentimental e-cards will fit the bill for you. Oh and are they funny.