Even on some supported devices, a bug in the Market software prevents Firefox from showing up. This may be related to the fairly recent Android Market app update. If you go to Settings/Applications/Market and choose "Uninstall" you can uninstall the update, and then search for and install Firefox from the marketplace. Or, if you have a supported phone, you can download the app directly by typing this address into your phone's browser: http://bit.ly/fxbeta3 (Note: To download the app directly for an AT&T phone, you will have to search for instructions on "sideloading" the APK file, since AT&T disables the option to install from non-Market sources.) Also, Firefox will not appear in the Market for most phones with incompatible hardware. You can check if your phone is supported here: https://wiki.mozilla.org/Mobile/Platforms/Android