My WOW/WTF moment was when I realized it won't import my SkypeOut contacts. Very frustrating :/
Or that you can't make a Skype video call unless if the other person has a webcam. Or that you can't chose which camera to use. Or that sometimes Skype will fail with a "general error" which requires restarting the phone to get Skype working again. Of course, you can just kill and restart the Skype thingy from the console, but it's much faster to just reboot the whole thing.

Despite for those very annoying (to me) flaws, it's a great machine.

The biggest wow this phone does is, it made me countless of sleepless nights investigating/playing with stuff.

WOW: Asterisks
WTF: choppy sip/skype calls

The app free intergrated chat clients is the bestest feature ever, makes it easy to have multiple coversations at once txt or IM it doesnt matter nice and quick...

p.s thats what she said lol

I used to hate skype on the n900 but magically it works now even on 3g ive been video calling my cousin alot latley at it works perfect, altho the video is abit choppy on 3g it works awsome.

My wow moment was when booting easy debian, installed xaos (fractals generator), edited audio with audacity, and in the maemo side when I ran aircrack 1st time and when I processed one image with caca libraries using cacaview
I have to try the tv out and USB Host features already

things I HATE :@:
having lots of apps running and the phone app receiving an incoming call crashing
desktop icons & widgets freezing

MAG's Sociality Facebook App is my recent wow.

Mostly for the ease in which I can check into "places" which was a pain in the arse using MicroB.

My wow moments has been,

when I opened the contacts app for the first time and realized how good it was integrated and linked into all the other apps like sms/IM, E-Mail, Skype and even OVI-Maps. That's what I ever expected from a contacts app, but didn't thought, that I will get it so soon. But my N900 made it!

And my second wow moment was, when I've seen, how fast this community creates a lot of really smart, clever and useful apps. Not all this thousands of rubbish apps that are in fact only a kind of a browser for a certain web page. That made me realize the nearly unlimited possibilities of this phone (Phone? No, it's not a Phone, it's more like a Computer! ;-)

My WOW moment was when my dad saw a QR code and asked me what it was and how to decode it. So, I went "hm... I'm sure there's a program for that!", found mBarcode, downloaded it and the QR plugin, ran it... and it immediately decoded the QR code when I waved my phone over it. Hooray for open source!

My second wow moment -- Or rather, not mine -- was when a neighbor of ours asked me something about his Internet connection(DSL speeds, I think). So, I whipped out my phone, loaded up our router config page, used the circle-gesture to zoom in on the spot I wanted while he watched. He just shook his head and said "amazing..." :P

1: Second day with the N900, poking around menus. FM ... (didn't bother to read it, scrolled down) memory -> 25 GB free. "Okay, let's listen to the radio. Wait. Where the **** is it? FM Transmitter.. let's set it to 93.1. Still no radi... O WAIT, FM TRANSMITTER? OMGWTFBBQ WOW THAT'S COOL"

2: Hmm, chat accounts, let's add my Facebook on there... OMGWTFBBQ IT ADDED ALL MY CONTACTS TO THE ADDRESS BOOK

Okay, that's from a former N95 user. Maemo + N900 is simply godly. Oh, did I mention the TV-B-Gone widget?

The big wow for me was that the n900 on the computing /hacking front outstrips all other phones and windows pcs then everyone starts goggling the phone but think it must be damn hard to use but then later when i need to a practicality (like browsing and other normal tasks) it again outsrips all other phones again astonishing
p.s everyone before i bought the phone my aunt looked it up and said dont buy it is way to big but after seeing it in action she forgot about that an said it looked good and started commenting on my sister satio (which is thinner than the n900) saying the phone is way too thick lol