You can create a Custom List from the browser by importing data from an Excel 2007 spreadsheet.
You can create an Excel 2007 spreadsheet from the browser and export data into it from a SharePoint list.
From within Excel 2007, you can export data held within an Excel table into a newly created SharePoint list.
You can synchronize changes between a SharePoint list and an Excel 2007 spreadsheet, which is a one-way synchronization process.