Take a look at http://www.cyrket.com/ , it's a web client for android's app market. You won't be able to download anything from the site, it's just a place where you can view the descriptions of the apps and their ratings/reviews.

It also listed the version number of these apps. Another service, aTrackDog is using its data (I think) to provide a version check service for all apps from the market (there's currently no new version notifications from Google's app market).

Cyrket.com does not look like a service from google, and there's is no publicly viewable database about the market from google (you can only access the market from a actual G1 phone). I am not sure where Cyrket get its data from. It probably actively harvest data from the market. The data on the site is almost real time, i.e. if I make changes to my app it will show up on cyrket very quickly.

So where did it get the data from so quickly? I am very curious... Perhaps the traffics between the app market and the G1 phone is not encrypted so they were sniffed out from the tubes?

by the way, here is a list of my apps

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Update:

looks like my guess was correct, this guy posted a blog post about how he can get live app market data http://strazzere.com/blog/?p=158

and installing the app market app on the emulator is also possible (judging from his screenshot)?