If you've been trying to use Googlebase's stores connection utility and have been getting errors, here ya go (note: this will only feed your store items to googlebase, not auctions and not core BINs)
How to Schedule your eBay Store Items for automatic upload to Google
Base:
1. Go to eBay and click "My eBay"
2. Click "Manage My Store" on the left side of the page
3. Click on "Listing Distribution" under promotional tools
4. Click "Activate your Store listings via RSS. (not sure if this
is needed for Google)
5. Click "Make a file of your Store Inventory listings available"
6. May need to wait at least 12 hours before you continue with
these instructions
7. When eBay provides you with a URL of your Google Base-specific
file, COPY THE URL - looks something like:
http://esssl.ebay.com/GetListings/yourstorename?fmt=g 8. Login to Google Base
9. Click the "Settings" tab
10. Change your Website URL to match the Google Base URL provided by
eBay - again, looks something like:
http://esssl.ebay.com/GetListings/yourstorename?fmt=g 11. Click the "My Items" tab
12. Click on the "Data Feeds" link
13. Click the "New Data Feed" button
14. Type a file name with the .xml extention - should be the name of
your store with no spaces - for example, "mystorename.xml"
15. Change the item type in the drop down menu to "Products"
16. Click the button that says: "Register data feed and continue to
formatting instructions"
17. Scroll down to the bottom of the page and click the button that
says: "I'm done formatting my file. Continue to upload"
18. If you need to, click the "My Items" tab, then click on the "Data
Feeds" link (or continue to step 19 below)
19. Click the "create" link next to Schedule
20. Choose when and how often you would like Google to upload your
file
21. Type the URL of the file - should match the URL provided by eBay
- the same one used in step 10 above
22. CLICK THE SCHEDULE BUTTON
23. Come back and check to see if your products have been uploaded as
scheduled - login to Google Base, click the "my items" tab, click the
"active items" link. You should see all of your store items listed
(they will not upload auction or fixed price listings)
source: http://www.powersellersunite.com/post-180348.html