* First boot
* First time watching videos via Facebook.com
* When organizing my widgets.
* XTerm!
* FM Transmitter
* WLM plugin for Availability menu & Pidgin IM
* First time WLAN. It is much powerful than my old N96.
* Rootsh and apt-get usage. It IS a Debian distro =)
* First time Conversation app, wrote some SMS really fast -i suck at it- thanks to QWERTY keyboard.
* Using LyricWiki and Shake2Control together.
* First time Speedometer app usage. I mostly dont use GPS features, so It was exciting to see how good it works.
* First time using CID port to remote control my TVs.
* PDF Reader. It is a great experience with N900's resolution.
* Playing OpenArena with accelometer
* Starting Debian LXDE and Iceweasel, OpenOffice, even "make" works with it.
* Playing Freeciv, emulating games with VGBA, The Mana World!
* SSH'ing into my device, using my PC remotely with my N900 (thanks to VLC) and vice versa.

I cant remember other things, Its a really exciting device, so It forces me to say "wow" every day.