The iPhone has some great built-in applications, but the surge of web apps even in these early days, is very interesting. Most of the things calling themselves “Apps” are little more than websites reformatted for the iPhone, but there are a few programs out there that are actually nice iPhone-like applications or interfaces.

Here are 5 of my favorites…

5) hahlo.com – Twitter for the iPhone. Hahlo is very much like Twitteriffic for the iPhone. It has a nice interface that is much more iPhone friendly than the official Twitter site, and it feels like an application when you’re using it. If you’re a fan of Twitter at all, you’ll find this one is a great time waister.

4) MockDock – Mock Dock imitates the look and feel of the actual iPhone desktop, and allows you to customize the applications that you have on it. It basically serves to link to you to those web apps that you’ll be commonly using. It’s nice looking, and has a good interface that almost makes you forget you’re in Safari.

3) JiveTalk – Bar none the best IM client for the iPhone to date. There are others that have a slicker looking interface, but JiveTalk looks like iChat, and allows you to connect to almost every IM client you can think of.

2) gOffice – While gOffice isn’t the only wordprocessor out there for the iPhone, it is the easiest to use that I have tried so far. It’s very basic, and does just what a wordprecessor on a device this size should do. It allows you to easily create documents and email them to yourself for future use. I actually like the look of Notepad on the iPhone itself better, but the major benefit of gOffice is the rotating keyboard of the Safari browser.

1)iNozbe – Nozbe is a web based GTD application (that’s Getting Things Done…if you don’t know what it is, Google it). iNozbie is a version of the software built specifically for the iPhone. If you’re into GTD this is a great way to organize your daily tasks, and you can integrate it with your desktop through their full web client.

So there you have my 5. What about you? Are their any apps you’re using that I didn’t mention here?