File Encryption Tools

I was wondering what people use for file encryption these days.

I'm not talking about disc encryption. I want a tool that I can use to encrypt a file (or an archive of files, like a ZIP folder), then either email to someone, or stick it on DropBox or some other public file storage service, or put it on a USB/CD/DVD for archiving.

Gone seem to be the days when PGP was free, but I loved that tool in those days.

So what do people use these days?