Really interesting concept. I don't have any experience at all with coding for Excel -- as best as I can tell, it's VBA under the covers? I really can't speak to that much more than what I can find online (mostly related to Twitter):

http://www.twopblog.com/2010/09/using-exce...lient-with.html

But, yeah, it seems like people have been able to get OAuth applications working in Excel as long as they construct everything by hand. ie, no obvious OAuth extensions to hook into.

I think that getting an interactive flow working correctly within Excel could be tricky, but once you retrieve a valid access token for a user (after having them go through the 3-legged OAuth steps), you could just keep refreshing that token within the Excel application. So...it seems possible? But a bit tricky to do. The flow described in the link above seems to only be constructing a request given a working access token/secret, while you'd need to build in something to retrieve the access token initially or refresh an existing functional access token, and then make the request.

Has anyone else played around with this?

Raphael,
    I know this is an old post, but I have an Excel workbook that successfully returns results using the API and OAuth. It was quite the ordeal. There is still some manual parts but I'm sure you could automate them somehow. For me it works. So if you still need it let me know. I'm not sure the best way to get it to you. Also if anyone else is interested let me know. I'm not sure I want to post my email. What would be an alternative to connect?

I haven't used GitHub much at all, but it does seem like a pretty straightforward solution for sharing code:

https://github.com/

You can set up a free account to make public repositories, you'd just need to be willing to install a Git client and learn how to use it. It also seems a bit more oriented towards straight code (ie, text) instead of a full Excel workbook, so I'm not sure if just a standard file hosting service might work better. Dropbox is the first one that comes to mind, but I'm sure there are a bunch more out there.

I would definitely also be interested to see how your workbook worked, though. :)

Is there a way to be notified of thread/post activity in this forum?

I posted a link to my spreadsheet, but it looks like it got removed.

If there's any way of you posting it again, I would be interested in seeing your spreadsheet.  Or email to ian dot viney at gmail dot com.

Is there anyway you could get this to me? I am very interested in seeing what you are doing. email is 
isaac _ 2004 @ yahoo

Appreciate it man

Dude please share how you did it! Been beating my head for days. 

I know this old, but since I was looking for this forever, I implemented it myself.  By all means leave comments on the page... http://code.google.com/p/vb6-oauth/