Most optical discs are a standard 12cm in diameter, are round, and besides some potential manufacturing incompatibilities with certain optical drives, are expected to load and be recognized in most systems. Despite this, some companies will distribute device drivers or other content on mini or oddly shaped optical discs.
While the novelty of nonstandard discs is fun, it does pose a problem for many systems that cannot read them. While there is no difference in the way the discs are read, the odd shapes will get them stuck in many slot-loading drives seen in MacBooks, MacBook Pros, Mac Minis, and iMac systems.
Usually, if a manufacturer has Mac-related drivers available for some hardware they will be distributed on standard-sized discs or also be available online from the manufacturer's Web site; however, if other options are not available and you need to read the content of a nonstandard disc, then you have several options for reading the disc if your system has a slot-loading drive.
CD or DVD Sharing
You can install the software using a tray-loading drive in another computer, by using Apple's "DVD or CD Sharing" feature. If you have another Mac handy, you can enable this feature in its "Sharing" system preferences, or if you have a Windows computer you can install Apple's "DVD or CD Sharing for Windows" software to enable use of its drive on your slot-loading Mac.
After the sharing software is installed and enabled, you will need to open the Terminal on your slot-loading Mac and enter the following two commands:
defaults write com.apple.NetworkBrowser EnableODiskBrowsing -bool true
defaults write com.apple.NetworkBrowser ODSSupported -bool true
Restart your Mac, and then insert a DVD in the second computer and access it from your slot-loading Mac's Finder sidebar.
An alternative to CD/DVD sharing is to use another computer to duplicate the mini DVD to a larger disc format (some office services like FedEx/Kinkos or other printing and office centers may do this). If you choose to use another Mac, you can do this with a program like Roxio's Toast, or Disk Utility (you will first need to create an image in Disk Utility, then burn the image to disc).
If you do not want to create a new disc, you can create a disk image with Disk Utility and copy that to your Mac via the network or with a USB thumb drive. When opened, the image will mount just like you inserted the disc, and provide you with the content to view and run.
To create a disk image, insert the disc (tray-loaded only), and then open Disk Utility. Select the disc, and choose the option "Disk Image from 'discname'..." in the "New Image" submenu of the File menu. Choose a location to save the image, and click "Ok."
Alternative optical drive
Beyond these options, you will need to get a third-party tray-loading USB or Firewire optical drive to use for viewing the CD. There are a variety of third-party solutions that can be purchased at places like Other World Computing (Mac-specific hardware), Frys, NewEgg, or any other computer electronics store. Most should just plug in and work without having to load any special software, but be sure the one you choose is a tray-loading drive and has been tested to work on the Mac.