James Dellow wrote last week on spreadsheets as an early mashup tool. I totally agree, and I don't think it was the first. Before RSS and web services provided a standard way to access data, ODBC was the defacto mechanism inside enterprises. In my book, Access predates Excel as an enterprise mashup tool. Information Workers truly embraced this, taking data sources from around their org, and pulling them together to create their own personal applications.
If anything Access was too successful, and in the post-millennium bug world, IT departments rushed to make their infrastructure more manageable by consolidating some solutions in centrally managed and hosted services, or mandating that these databases be removed. Access was then frequently removed from the standard desktop deployment of Office.
It's easy to spot the obvious flaw with this strategy. Removing the tool of choice for enterprise mashups doesn't stop demand. Enter Excel.
Like Access it provides a simple way to get data from external sources and has tools to make it effective as a very simple flat-file database. It has great data visualisation capabilities, but the thing that made Excel the mashup king was the macro recorder. With this, anyone could create very rich no-code solutions.
I was speaking with a customer from the IT department of a large enterprise recently who was telling me that they are planning to send the home-brew Excel solutions in their org the same way as Access solutions. What they are failing to consider this time however, is that in the battle between users and the IT department the stakes just got higher. Take away the users' favourite mashup tool today, and the result will be confidential data pasted it into Web 2.0 services on the Internet simply to enable them to get their job done.