There are a few options here.

• iPhone Configuration Utility (yeah, that's what it's called)
  Manual deployment and management, that is, requiring IT to touch each device. Apple has some guides on doing this.
  http://www.apple.com/support/iphone/enterprise
• OS X Lion Server
  Lion has the ability to manage the devices over-the-air (Profile Manager).
  http://www.apple.com/macosx/server/features
• Mobile Device Management (MDM) software
  There's a list of MDM vendors which support the iPad on the Apple “iPad for businesses” page.
  http://www.apple.com/ipad/business/integration/mdm/
• Microsoft Exchange
  When using Exchange ActiveSync, iOS understand and will enforce a subset of Exchange policies starting with Exchange 2003, and increasing with 2007 and 2010 versions. For a full list, see:
  http://developer.apple.com/library/ios/#featuredarticles/FA_Exchange_ActiveSync_and_iOS4_Devices/Introduction/Introduction.html

I've been using Airwatch's MDM software. They market it as $3/device-month. In reality, they bill ahead for the year, the minimum purchase is 25 devices, and there is a $1,500 activation fee. Still, it's been a great tool. Over-the-air management requires some infrastructure ahead of time. Mainly, you need an Apple Developer Account, which is $300/year. You need a valid Apple ID and to fill out the APNs Certificate Signing Request as described at http://www.apple.com/iphone/business/integration/mdm/. This allows Apple to authenticate your Apple Push Notifications for your devices (if you change any configurations, they're pushed out). It's not optional. It's mandatory. http://developer.apple.com/programs/start/it/ https://identity.apple.com/pushcert/

All these management options allow IT departments to deploy “profiles” to iOS devices. These profiles are, in essence, encapsulated policies and settings. Want to enforce a password policy? Or give company WiFi credentials? These can be done through profiles. Lion and MDMs give the additional ability to add or change, or remove profiles over-the-air (without touching the devices). This means also granting the ability to wipe company data even wipe the entire device.