SQL Everything
General
Microsoft provides a set of database access components (see Wikipedia), of which OLE DB and its JET installable ISAM drivers can be used to access arbitrary data sources directly from within SQL.
Named Formula
General
When working with spreadsheets, you usually create a magnitude of formulas. Having comprehensive and verifyable formulas is crucial for the understanding and maintenance of any spreadsheet. Most experienced users have therefore already switched to names instead of cell references.
