Email’s great, but those receipts compete for attention with email from your mom, friends, colleagues, etc. which makes them hard to find when you’re trying to look up past purchases, track packages or find the store you bought some shoes from a year ago.

Enter Shopdeck. Shopdeck is a personalized, filtered shopping experience.

Thanks to OAuth, Shopdeck lets you grant access to your Yahoo! and Google mail accounts. Once authorized, the app mines your email for receipts and order invoices, parses those matches for the useful information, and aggregates it inside Shopdeck.

The app’s home screen becomes a dashboard of your favorite stores… not a random set of stores you don’t care about. These are the stores from which you’ve already made purchases.

Similarly from those same parsed emails, you can get quick access to recent (and long-past) purchases, track the associated packages, and quickly go to site for a particular invoice detail.

Plus, you now have a launcher, search box, and history for the stores you already trust.

And, when I say “now,” I really mean “soon.” Shopdeck was demo’d at iPadDevCamp (thanks to the awesome skills of one Zach Graves), but still has some work to do before submitting to Apple.

In the meantime, see more at Shopdeckapp.com and @shopdeckapp.

(Update: Name updated to Shopdeck to avoid trademark issues.)

We have all the official information up on the Yahoo! Developer Network blog, as well as the official open Hack Day site.

And, as with last year’s event here in Sunnyvale, this will be free, open to (and expressly for) non-Yahoo! employees, and provide a 24-hour, beer-and-pizza-fueled social environment within which folks can build and demonstrate unique product ideas and enhancements. Unlike last year’s event, though, this one will be held in a palace overlooking London.

The whole YDN team will be there for the event, as well as a number of US- and UK-based Yahoo! folks. I’ll personally be in London Wed, June 13, through Sunday, June 17, so if you’ll be there too (or happen to live there), drop me a line.

But most importantly, come out and make something.

Other posts about the event:

• Matt McAlister, Yahoo! co-conspirator
• Matt Cashmore, event producer on BBC’s Backstage team
• Ian Forrester, also a member of the Backstage team
• Chris Riley, excited participant

PS: Happy Cinco de Micah!

Every 3 months, Yahoos from all parts of the company have 24 hours to build new products (or enhancements to existing products) with the express goal of showcasing their work in front of the company… and its top executives.

It’s what we’ve dubbed “Hack Day,” and it’s been remarkably successful at bubbling up top ideas and talent to decision makers internally… and then out to our users.*

So, it was out of our most recent event that Loc Amigos emerged. Fellow Developer Network crony Jason Levitt drummed up the idea of scouring the address books of a user’s different mail accounts to find which social networks these contacts may already be a part of… sure beats the current approach most use of sending emails to everyone in your address book. Using the Yahoo! Mail APIs as well as some screen-scrapers for Hotmail, AOL Mail, and Gmail, as well as the YUI user interface libraries, Jason worked with Kathleen Watkins and I to quickly assemble a working version of the product.

Does it work? Absolutely. Is it the best user interface for this sort of challenge? No way… but, it demonstrates something very important: a small, nimble team quickly working on a proof-of-concept can take a cool idea, get a working prototype, and now take it into usability labs to get real user feedback.

It’s this rapid, entrepreneurial spirit that is still fostered inside Yahoo!, and makes it a very exciting place to work. Even more exciting, the Developer Network (of which I’m now a part of) works on projects like this all the time in efforts to demonstrate and test the very APIs and Web Services we promote. It’s hard to imagine a more collaborative, inspiring environment, especially one built to encourage others (whether individual designers/developers, startups, or even our competitors) to succeed in similar ways using our (and others’) tools.

* For more on what Hack Day is, and why it rocks, see Chad Dickerson’s post on Yahoo! Hack Days as well as Matt McAlister’s Top 10 Reasons Hack Day Rocks.