市场：//搜索？q = pname：包
You can post a link to an android market application by useing a link that looks like:
While browsing the market, is it possible to find an app's package name? Or is there a convenient way to get or share a link to a market app?
Is there any way to post a link to a market app that normal (non-android) browsers can make use of?
This isn't possible, simply for the fact that except for the few apps that are featured on the Android Market site, there isn't a way to browse the catalog of apps from anything but an Android device. You can link to the app if it's on the site, and if it's not your best bet is to see if the author has set up a web page for the app.
Google did say in their IO keynote (31:08) that they're working on a web interface for the market and demoed buying an app in the browser and having it pushed to the device instantly. It's likely that that interface will have the ability to link to specific apps, but until then it's not possible.
There are a few 3rd party websites that do let you browse and search the Android Market. Most of these show all the text description, screenshots, review comments and rating from the Market as well as having a QR code 2D barcode that you can scan with your Android phone to jump straight to that app's page in the on-phone Market app. Doing a search in any of those should show you the full package name (usually in the page URL as well as buried in the page).
A few of them (off the top of my head and in no real order) are AndroLib, Cyrket and AppBrain.