We have seen the official Apple Keyboard dock which gets the work done if you are not much into the onscreen keyboard of iPad. But portability of the keyboard can be a issue sometimes considering iPad is a mobile device and carrying a extra pair of keyboard seems overkill. But if you still need a hard keyboard to type on and need it easy to carry around, then EFO Mini Bluetooth keyboard might interest you. Well it seems to work great and considering its about a size of a credit card, it sure is portable enough.

Features list I got in the mail from the guys behind the keyboard :
• Easy To Use
• With Full Function Keys (F1 to F12), Tab and Cltr+Alt+Del keys
• Multi-Media Key (Play, Pause, Next, Previous, Mute, Volume Up, Volume Down)
• Tailor-made for handheld device, backlit buttons
• Bluetooth, for iPad, iPhone & Smartphone (Successfully tested on iPad and iPhone 4 that it can directly connect to them. For iPhone 3 and Smartphone, additional software is required)
• Mini and Portable
Product Description
• Wireless remote control of your handheld devices including your iPad, iPhone and Smartphone
• Bluetooth wireless
• Enhances handheld device control with Remote Control, just like your TV Remote Control
• Adds a professional lecturing and teaching tool to presentations
• Convenient size
• Plug and play
• Backlit keyboard for comfortable operation in darkened room

Video Showing the Keyboard In Action :

Well, again its personal choice on how you mobile you want your keyboard it to be and pretty sure nothing can beat this. The keyboard is still in production and you can preorder it for $32 from the Link and it will start shipping from early September 2010.