I never really understood would I want to use sticky notes/cards  in my agile projects rather than use a software tools. After all we write software for others - how can we say that software is not a good enough solution for us ?
For instance, in our team we use Mingle by Thoughtworks. I think it is one of the best tools for project management I've ever used.  Its serves us well for sprint planning, daily scrums etc. Among other things it gives you "digital" sticky notes which you can drag around to move between statuses or whatnot - just perfect.

And yet, last week when we were pushing for completing our first major milestone I decided to try real sticky notes, and finally I understood the difference - constant visibility. Computerized tasks seem to be just as accessible as physical cards but in fact they aren't. Yes, everyone can see the status whenever they want. But the fact that you can doesn't mean that you do. Digital cards don't have the "in-your-face" kind of effect that always visible notes has. I've seen a notable  difference in maintaining the dev team's focus and making managers (the CEO in my case) feel they are in the loop and that progress is constantly made.
My conclusion is clear. While I still use electronic tools, I guess, until we'd have large enough e-ink boards to allow us to get the same effect physicals cards give us I'll just have to keep restocking my sticky notes inventory :)