WTF

There's a wide range of apps I use on a daily basis for work, fun and productivity. What exactly do I use?
Productivity
Things: all my to do's and projects are well organised thanks to this app. I wish Things supported push notifications to remind me of some important stuff that have to be done by a certain date.
Calendar is mostly used to keep track of my courses for school. I always set the alert to '1 day before' and '2 hours before' to make sure I never forget anything. All my calendars are pushed to the cloud with MobileMe.
SimpleNote is a fast, no-nonsense note app. The big difference with Apple's Notes app is that it syncs automatically with a web app. If you make changes in the web app, they are automatically synced to your iPhone.
Communication
Mail: like calendars, e-mails are pushed to my iPhone with MobileMe. I don't have a data subscription so I turn this off when I'm on the road. Tip: by turning Push off, you save a lot of battery power. If you still want to receive mail, turn Fetch on and set it to 'Hourly'.
Tweetie: I use this more than once during the day. I have two accounts: one for personal stuff and one for App Temple. I'm always amazed how many tweets I receive in the morning when I wake up.
Ping: I've got some friends abroad so this app comes in handy. It's great and saves me €0,40 per SMS sent internationally.
Messages: my subscription includes unlimited free text messages 24/7. I send about 10 messages a day on average.
Fun
Facebook can be used for communication but to me, it's just for fun and photos. Most people in Belgium don't use Twitter as heavily as Facebook.
iMob is really addictive and I play this game way too much. Feel free to add me to your mob: 335.430.114.
What about you, what iPhone apps do you use on a daily basis?
Undercover, the theft-recovery app for the Mac is also available for the iPhone and iPod touch and now supports push notifications. The app helps you locate your lost or stolen device and can even be remotely launched from a web interface using push notifications.

When you launch the app for the first time, you have to fill in your e-mail and iPhone name. An e-mail will be sent with a link to set a password and complete the registration. With your new account, you can access the web interface where you can track your iPhone and send a push notification, just like MobileMe. Your device's location is displayed on Google Maps and you even have the ability to report it lost or stolen.

This app can come in handy if you're not a MobileMe subscriber. For €3,99, it's a steal.
Do you use a theft-recovery app for the iPhone or iPod touch?

Ping! is a handy little app to send free text messages to fellow iPhone and iPod touch users. Everything happens via WiFi, 3G or Edge so there are no additional costs for sending messages. You just need to create a free Ping! ID when you startup the app for the first time and there's no need to login or out afterwards.
The interface is similar to Apple's Messages app and supports landscape typing. The app is very useful for when you're travelling and want to limit the roaming charges. The app has a very fast startup time and messages are delivered instantly. Ping! does Push Notifications too.
Update
Unlike WhatsApp, another iPhone-2-iPhone messaging app, Ping! doesn't ask for your phone number.
The good
The bad
Personally, I only know two people with an iPhone.
Do you use iPhone-2-iPhone messengers? Which one?
These are the very best iPhone apps of most I use on my daily life.

With more than 85,000 applications available for the iPhone and iPod touch, there is almost certainly an app for whatever it is you love. I've been working on a new book that will feature descriptions of the best apps in more than a dozen categories and have been spending a lot of quality time testing various ones. Here are a few that really impressed me:
This excites me. I've become a fan of Lala lately. I love the opportunity to listen to entire albums for free before buying (30 seconds doesn't do it for me), and I've bought a number of Web albums for $1 and appreciated the opportunity to listen as much as I want before committing to buying the (high-quality, non-DRM) MP3 files. But streaming...that's a dream come true! I didn't dare to hope. Bet Apple kills it.
Da sammelt sich innerhalb kurzer Zeit schon einiges an Apps auf dem iPhone an welche ich nicht mehr missen möchte.
Vom Twitter-Client über QuadCamera bis hin zur eBay-Applikation. Aber trotzdem ist man ja immer auf der Suche. Spätestens Abends wenn ich im Bett liege und meistens noch einen kurzen Gruß via Twitter in die digitalen Weiten huste huscht mein Finger meist noch kurz auf den App-Store-Button...
Falls Ihr einen Tip für mich habt was hier auf keinen Fall fehlen sollte.....gerne her damit!