Sometimes you just want to manipulate data in your spreadsheed in place with the help of SQL but without having to go through the ceremony of importing and exporting to/from a database. For instance, with this plugin you can use regular expressions (replacex function) to transform data in a column, or you can do a join. If that's all you need to do, the overhead of importing/exporting is not worthit, and having convenient SQL+Regex can be a nice time saver. (disclaimer: I'm the author)
SQLite -- plus, if you need it, some open source GUI -- and you are done. No pain of bending Excel to do what you want; none of the horrors of Access and its cludgy-flavoured SQL. If you really need it ultimately in Excel, I'm sure there's an ODBC driver you can use to get a view on the data.