I despise e-cards.
Not because of their stigma, which suggests your neglect and lack of planning in sending someone an honest-to-goodness paper card, but because the majority of the sites I've used over the years are packed to the gills with gaudy advertising and difficult to navigate UI. That experience ultimately ends up falling on your recipients, who are sent there to dig through the muck to get their Flash-animated hello.
Luckily, the same can't be said about a site that launched earlier this week called Rattlebox. You're not going to find cute flowery cards here. In fact, all of the "cards" are video clips that have been put to music and given spots for you to add customized text. The majority of them are safe to send to your mom or a co-worker, but there's some crude stuff thrown in for good measure.
The entire process of picking out a video and sending it off to someone only takes a minute or two, and the categorization is well done. You've got a handful of options for sending out your creation either via e-mail and IM or to end up on your friend's social networking profile. While there are still ads on the site, they're tastefully done, and only show up when your video is processing with your customized text, although I would like to see a volume control option to mute the sound.
I'm still wary of sending an e-card over an e-mail or making a phone call, but those who enjoy them should give Rattlebox a look.