One of the advantages of popular open source projects like Google Chrome is that there will almost always be forks of the original project that will try to meet some of the shortcomings of the project, or improve upon it by porting it on different platforms that the project is yet to officially support. Google chrome is not immune to such fork / clone projects and each of them tries to meet some of the features that original project lacks.
1) SRWare Iron: This fork works on the original project by stripping out the features that has privacy concerns in the form of unique ID or submissions of entries to Google to generate suggestions. Apart from that it is an exact replica of the original Google Chrome. Binary available for windows only.
2) Stainless: What started as a demo to demonstrate multi-processing architecture, ended up being a full-fledged browser with improvements that are not available on the original Chrome projects. Including separate unique sessions on the same website on individual tabs which can be saved as bookmarks. Since the official Chrome is yet to release a binary build for Mac OSX this is a great way to try out chrome on OSX while you wait for the official release. Download it here.
3) CrossOver Chromium: This is perhaps the least stable clone of the three. Well, it is not really a clone in the traditional sense. It is windows Chrome bundled with the technology used by Wine, which installs some windows application on non-compatible platforms like OS X and Linux. The idea is to showcase the power of Wine in installing windows applications on other platforms. You can download it here.
Google Chrome developers are already working on native builds for Linux and OSX but they are still few months away.