Afloat 2 is an extremely simple Mac application that lets you keep a window “on top” of all other windows. It adds this option in the Window menu of any Cocoa application.
This is useful when you want to keep an application active, and the app doesn’t already provide the functionality to do this.

Afloat also has the ability to make a window transparent. This actually works really well. The window becomes more opaque when you mouse over it, and more transparent when you mouse off.
This makes keeping windows “on top” much more attractive. Making an inactive window transparent allows you to focus more on your current window.
Below is an example of what this looks like. On the left Adium is “on top” but my mouse is over another application. On the right, my mouse is over Adium, causing it to become opaque.
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Finally, Afloat gives you an easy way to keep a window on all spaces.

Of course, there’s already a way to do this in Expose & Spaces preferences pane. Under “Space” select “Every Space.”

Afloat 2 isn’t a must download for all users, but if you’re looking for a way to keep windows active–this seems like a great option.
Thanks Alex for the tip! Submit A Mac Tip and get some traffic to your blog.
Discerptor
Michael Zhao
For transparency, go to the Appearance tab and slide the opacity slider to whatever and for "All Spaces" go to Advanced, then click on the Contact List tab and check the box on the bottom. For float, click the drag menu next to "Show contact list:" and select Above April 7th, 2008 at 8:54 pm
Brad Jasper
As I described in the tip, it goes opaque when you mouse over and transparent when you mouse off. April 7th, 2008 at 9:04 pm
Discerptor
Alex Hwang
Thanks for looking at my "tip"! April 8th, 2008 at 4:28 pm
Brad Jasper
I always like hearing about obscure application. At first I wasn't sold on keeping windows on top, but once I discovered the transparency on mouse over feature I was impressed.
Simple, but gets the job done.
Thank you for submitting it Alex.
- Brad April 8th, 2008 at 5:05 pm
Alex Hwang
Brad Jasper
Sign up at Gravatar.com using your e-mail address. April 10th, 2008 at 7:13 am