I mostly use MySQL for ad hoc analytical work for specific projects – the sort of work where Microsoft’s Access product just doesn’t cut it because of the size of the data-sets involved. However, this is really just the tip of the ice-berg for MySQL, which powers a large proportion (I don’t really have any idea on the actual stats) of the web’s sites and more.
There are competing products, free and open-source. For some of the analysis that I do, a more specifically oriented statistics package like R or SAS (which is particularly good for large datasets) may also be worthwhile considering.
However, if you’re interested in finding out a little more about MySQL, you can visit their homepage or their developers’ zone. Also, the following two links provide brief pros and cons of using MySQL.
For those of you who complain that Excel only has 65535 rows (although I hear rumours of more rows in the latest or upcoming version?), perhaps you should consider using the correct tool for the job? Give MySQL a look.