Fritillaria are the lilies of spring. The last of this season's plants are blooming now, and many of the early blooming sorts are already dormant for the summer. Fritillaria will probably never be common garden plants in our climate, but if you are willing to go to a bit of trouble many will respond well. In my experience the only species likely to persist as a garden plant is Fritillaria meleagris. Most of the Fritillaria here are grown in containers in cold frames. Most start into growth very early, and it's not unknown for unprotected plants in full bloom to be caught by overnight freezes. When this happens, the plants temporarily collapse and eventually rise up again. It's hard to believe that this is good for them, but they do seem to endure such conditions without obvious ill effect.
Check on the title line above ("The lilies of spring") to link to my Fritillaria gallery: the 2008 additions will be arriving soon.