It seems everyone and their brother has written a CSS Font Stacks blog post, but none that I've found give Myriad Pro/Myriad much attention. Yes, I know Myriad Pro is not web safe - hence the stack. Just want to get some input on some sensible fallbacks. Thanks!
You can test out unconventional stacks here: http://www.typetester.org/
font-family: "Myriad Pro", "Gill Sans", "Gill Sans MT", Calibri, sans-serif;
Would look like a good match, for size and style, as Gill Sans is a similar size and common on Macs, with Calibri meeting the same criteria for Windows.
(I've just added Myriad Pro to a suitable stack from here: http://www.awayback.com/revised-font-stack/ )
I'd recommend using Lucida Grande instead of Myriad Pro, as side by side they differ only slightly (try tweaking the tracking). You'll maintain compatibility then.
So I'd go,
font-family: "Lucida Grande", "Lucida Sans Unicode", Arial, sans-serif; letter-spacing: -1px;
Give it a go. Let me know how you get on.
Simon, I created this whole account just to say you are a genius. I would have wasted hours figuring this out and it looks great. Thanks!