Does anyone know if there is, or will be a Droid app that will let me scan barcode items at the grocery store,
and total or keep track of my bill for family budgeting?
Not that I'm aware of. You could use ShopSavvy from the market which will keep a daily history of things scanned, but that's about as close as you can get.
The problem is that the SKU is unique to each store/chain so the database for such an app would have to be massive. Additionally, there would be no way for the app to know what items were on sale based on the SKU alone.
My local Publix has corn on the cob for sale this week - 5 for $5... my phone couldn't possibly know that unless it was somehow connected to their internal system.
There are free apps on the market for grocery lists + budgeting, but they all require you manually enter the product name and the price.