How to set the height for a specific row in a “longtable”?

Question

I have a "longtable" and I need a couple of rows to be "taller" than the others. Is it possible to specify a fixed height for a specific row?

Answer 1

\rule{0pt}{whatever_you_want}

is the better choice and if you need a depth:

\rule[shift]{0pt}{whatever_you_want}

Answer 2

Oh well, I've created an empty box within the cell, like this:

\vbox to 1cm {\vfil
\hbox to 3cm{}%
\vfil
}

Probably not the best method to do this, but it works.