Question: Just like the newly presented iMessage but instead of just between iOS devices, with the Mac too.

I've looked at Handoff. It can only send links to the iPhone from the Mac.

I've looked at Droplr. It requires public sharing on a Twitter account. Not what I want.

I've been using email and have been recommended Evernote. But these solutions require a document that I must create, wait to sync, and/or later delete to free up clutter. I just want to send a quick message.

I just want an app/application pair that can quickly share links, notes, and pictures between devices, like iMessage.

Does what I desire exist?

Answer: 
The best solution I have found for quick and seamless transfer of clips, pictures and links is [PasteBot](http://tapbots.com/software/pastebot/).

Currently it works for WiFi sync, but in practice, my phone is always with me when I get home and I don't really need the data to get to the mac sooner than when I'm back home. I would expect them to try to extend the syncing to use the iCloud API announced but still in beta testing - but there's no promise it will work just like iMessage over the air using sync.

I don't use PasteBot to share links since I use [pinboard.in](http://pinboard.in/howto/) and [instapaper](http://www.instapaper.com/faq) for that and they work so much better for me than getting the links over a clipboard. The announced Reading List sync between iOS and Safari on the desktop might also serve your needs.

Good luck - there are many options and hopefully you find one that works best for you.
[Evernote](http://www.evernote.com/) does this. Photos, notes, screenshots, audio memos, etc. can be captured and shared between your Mac and iPhone.