go to listings feeds (under manage store in my ebay)
http://cgi6.ebay.com/ws/eBayISAPI.dll?StoreMgmtExportListings
where it says "search engine and comparison sites" click the button for "make a file of store inventory listings available"
then take the file that it generates (an xml file) and save it to your computer.
then go to
http://www.gamegiants.net/gbase
and run the file through the gbase converter
Take the resulting tab deliminated txt file and open it in excel (or openoffice). the converter will put some invalid stuff in the finished file, so you will need to edit it. But, it will give you an idea of what the tab deliminated file should look like.
as for your question about 3rd party access, that's a whole different thing. that's to allow places like auctive to do things on ebay on your behalf (such as launch listings)
also, you should be aware of google's rules about auction site listings
1) Your Google Base items must be created with an item type of "products."
2) Your Google Base items must include the fixed "Buy It Now" price listed on your product page. (We're not accepting auctions without a fixed price at this time.)
3) The expiration date of your Google Base items must match the expiration date of your auction.
as you can see, the converter didnt put anything in expiration field, and you'll find there's other issues too.
when you save it, be sure to save it as a tab deliminated txt file.
(my apologies to lisa - didnt mean to hijack your thread)