I'm a vintage girl, especially when it comes to stationery, so I was excited to find the Writeables site that has a ton of vintage-looking cards. The card design I originally found in a New York card store isn't here (cute pink elephant picking a flower), but I may like the happy cake (above, $3) even better.

Of course, if you're shopping online, you may want to go with their boxed cards ($14 for six), which include matching stickers. My favorite is this mermaid set but there's quite the selection on the site.