Well I sent a message to BikeFriday and thought I'd post their response here in case anyone else looks for a trainer for a BikeFriday.

Here is the message I sent:

I purchased a Petite Crusoe earlier in the year, and I am considering
getting a trainer, or rollers and a fork stand. Would putting the bike
on a trainer or on rollers and a fork stand cause any problems?

I was considering something like this.
http://www.hoenig.biz/Trainers/index.shtml
Thanks, Sylvia

Here's their response:

Hi Sylvia.

We've used our bikes with trainers such as the CycleOps with it's small
wheel adapter. The trainers on the page you referred should work too,
but we haven't tried them yet so there may be some technical issues that
need a work around or two.