@Radu it's basically like having an unlimited plan but limited to 30MB data in 24hrs time. Any web app would work, even JoikuSpot/MobileHotspot.

Back to topic, YES, this has happened to me once! It was recent too. It lasted for about 2 days until I logged in to my.T-mobile account and disabled Web Gaurd (Net nanny that blocks certain sites). After that, I suddenly lost connection, and that was the end of my free Web pass. If I hadn't done anything I would've had unlimited 3G forever if I wanted.

I should also mention that I've had expierences where I bought a Web DayPass and it didn't connect to 3G (happened a couple of times so I assumed T-Mobile was giving me free Web passes or something). Anyway, I was able to reboot my N900 and still auto-log on to 3G without any payments. It was full 3G speed with no limits, and I loved it! Great T-Mobile glitch indeed (or was it?), but too bad on my part.. Good to see that this is working for some people out there.

So whatever you do! DO NOT sign in to your my.T-Mobile account.

// Roth