You'd probably already know how much Simplenote is amazing. It's a little iPhone note taking application that sync every note over the cloud, allowing you access the notes you took from your mobile device on your desktop. It's very cool. But even better, the developers launched an API service that let other developers create application that integrate with Simplenote.
Nottingham is an elegant, simple notepad for Mac OS X. It's very similar to Notational Velocity: you have a top search field, the notes list and the text field. That's it.
From the search field you can either search or create a new note, you just have to hit Enter. Once you've created a new note you can start typing without the need to save everytime. Yeah, much like Notational.
What makes this Notthingam thing stand out it's that it seamlessly integrates with Simplenote: select the sync option from the menu and here you go, all your Simplenote notes in one place. Unlike many other sync services, you can also delete the notes you have on your account. Awesome.
Notthingam free supports up to 10 notes, so if you'd like to use as a Simplenote client I think it's just perfect. If you'd like to store unlimited notes you can purchase a full unlocked version here.