SwiftKey X is a popular alternative to the standard Android keyboard, and the developers are in the habit of continually improving it. In addition to a Halloween pumpkin theme last month, they're trying out multi-touch features in a new alpha release. The download has been spread around by the developers, but only VIP members (i.e. those who have paid for SwiftKey X) can access it.
For the present, TouchType is recommending that you not use the alpha as your only keyboard entry, because it disables some of the full version's features and has considerable bugs. The alpha is for enthusiasts to try out, and will help the developers iron out the kinks in the new multitouch system. The app download will only be active for two weeks - after the testing period, both free and paid users will have to wait until the main app is updated in the Market.
SwiftKey X has swiftly risen to the top of the virtual keyboard replacement crowd, and is currently sitting with a 4.5 review rating and an Editor's Choice highlight in the Android Market. There are of course dozens of alternatives, but SwiftKey distinguishes itself with a custom text prediction engine. You can download a free version from the Android Market to try it out for a month, and the full $3.99 version will get you early access to the alpha.