The Apple iPhone was born as a primarily consumer-oriented smartphone. But, Apple managed to change the smartphone rules and blur the lines between consumer and business tools--eventually being embraced by many IT admins and invading the business world.With 200,000 apps available, it is a virtual certainty that no matter what you want to do on the iPhone, "there's an app for that". However, 200,000 apps also means that there are tens of thousands of apps that are completely useless. Suffice it to say that none of the 150 or so apps with the word "fart" in them will be suitable in a business environment.To help sift through the nonsense and find the apps that will increase the value of the iPhone as a business tool and help you work more productively on the go, here are five must-have apps.Documents to Go Premium. Despite Google's intense efforts to compete in the office productivity arena, the fact is that Microsoft has a virtual monopoly on the market. Until Microsoft gets a clue and creates Microsoft Office apps for other smartphone platforms like the iPhone, business professionals that rely on Microsoft Office at their desktop will appreciate having Documents to Go Premium on the iPhone.Documents to Go Premium enables iPhone users to view, edit, and create Word, Excel, and view PowerPoint files, as well as viewing PDF and iWork files. It has a desktop app counterpart that will sync files between the desktop and the iPhone (or iPad) via Wi-Fi.Dataviz also offers Documents to Go for only $9.99, but the extra $5 for Documents to Go Premium is worth it. It provides the ability to edit PowerPoint files as well as viewing them, and it works with online file storage services such as Google Docs, Dropbox, Box.net, iDisk, and SugarSync.Taska. I really love Microsoft OneNote on my desktop, but unfortunately there is no OneNote iPhone app. Taska is an excellent alternative, though, for creating and managing tasks and to-do lists on the iPhone. You can organize and prioritize tasks, and easily make recurring tasks. It is both intuitive and flexible, allowing you to manage your tasks in a way that makes sense to you.One unique function of Taska is the ability to map out tasks and order them based on geographic proximity to one another so you can accomplish them more efficiently while you are out and about. My one complaint about Taska is that it is not a universal app--meaning you have to pay $4.99 for the iPhone version, then pay an additional $4.99 if you would also like to use the iPad version of Taska.Dragon Dictation. Typing text messages, instant messages, and e-mails on the tiny virtual keyboard can be difficult. Dragon Dictation is an excellent voice recognition app that translates your spoken words into text. It is fast, and it is by far the most accurate voice-to-text translation technology I have used.Dragon Dictation lets you easily turn your voice into text, and put it to use with a single click. From within Dragon Dictation you can post your text as a Facebook status update, or Twitter tweet, send it as an e-mail or text message, or copy it to the iPhone clipboard to use in any other app that allows you to paste in text.Best of all, Dragon Dictation is free.Cisco WebEx Meeting Center. This free app from Cisco lets you attend meetings anywhere in the world, any time from your iPhone--whether on a 3G or Wi-Fi connection. You can schedule, attend, and start WebEx meetings using the iPhone app.Meeting attendees can view meetings along with integrated audio, and can also view documents, applications, and screen-sharing within the meeting. The iPhone app also lets you see who else is attending the meeting, and engage in private or group chats with other attendees.WebEx subscribers who have the tools installed on their PC can transfer a meeting--while it's in progress--from the iPhone to a PC with a flick of the wrist.