Apple Remote + Spotify

I know that there are a few ways to add support for various apps, but you might want to consider paying for Mira.

I've used it for a few 10.6 and 10.7 laptops and it works great.

There's also Remote Buddy, although I've not tried it personally.

What application are you interested in exactly?

One workaround could be to make Spotify scrobble to Last.fm (in preferences), and then get the song title from Last.fm. Iirc, there is a plugin for Adium that does this. Caveat: there'll be some delay in the updates when using this method.