I've written a Visual Basic (Windows) program called WFret that not only prints out charts showing fret spacing for any scale length, but also prints out templates you can glue to your fretboard blank so you won't go blind trying to mark the fret positions before you slot. It's available for free download at the Musical Instrument Makers Forum, www.mimf.com. You might have to register (also free) to gain access to the software library. Warning - it's about 3MB so it takes a while to download - this is because of all the fancy Window handling code libraries.

The 1/17 ratio is inaccurate - 1/18 is closer, the actual value is 1/17.817.