The easiest way to gain access to the Market - and improve the overall performance of your tablet - is to ditch the Tap-n-Tap user interface and install one of the many custom "ROM's" out there.
IOW, you're basically jailbreaking or hacking your tablet and installing a different "OS". Most of these not only give you full Market access, but also enable Flash and other useful functionalities.
I got my G Tablet Saturday and flashed the ROM to TNT Lite yesterday. It requires a little research and installation of some "helper" software, but anyone with medium tech ability can do it. Just google "install TNT Lite on G tablet" and you'll find guides and even YouTube videos that walk you through it.
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