Should I include a <meta generator> tag?

A benefit (or a con?) is that you can show up in searches done for generator.

I've never seen a tag formatted like that before, with an attribute called generator and the generating software as its value. Usually you'll see it presented as name="generator" and the generating software as its corresponding content, for example:

<meta name="generator" content="WordPress 3.0.1" /> <!-- leave this for stats -->

Previously I was unaware of any standard for this, however it looks like HTML5 has gone ahead and standardized the use of "generator" as a metadata name. It describes it thus:

The value must be a free-form string that identifies one of the software packages used to generate the document. This value must not be used on pages whose markup is not generated by software, e.g. pages whose markup was written by a user in a text editor.

In the past when dynamic web apps weren't that prevalent, certain web site editors, like FrontPage (there, I said it), would automatically insert generator tags when you create new HTML documents or publish sites using them. This was taken to mean "This page was created using FrontPage". I don't think any modern editors or IDEs do this anymore, but I could be wrong. It's definitely commonly used in dynamic web apps today, however.