Thought I'd share, as I've been looking for a way to do this for a while, and gave up on the sluggish/crash-ridden virtualpc solutions.
For image files containing just .mds and .mdf, it's sufficient to rename the .mdf to .iso. Burn this file as image file in Toast.
For image-files containing an .md0-file, You need "Split and Concat"
http://download.com.com/3000-2179-10212101.html
Here's how:
(Leave the .mds-file alone - You don't need it, but it's not in the way either).
Rename the other files, for instance:
if Your file batch looks like this:
File.mds - (8kB)
File.mdf - (3,99GB)
File.md0 - (69,9MB)
rename them to
File.mds - (8kB)
File.iso.001 - (3,99GB)
File.iso.002 - (69,9MB)
Of course, the .mdf is the first - and main - file, so it should be named 001.
Open Split and Concat,
click on "concat", and locate and choose the two .iso files (click the first and shift-click the other to select both). Click "open".
Now, Split and Concat should present You with a nice progress bar, so sit back and relax.
When finished (it takes no more than a few minutes), check the size of the new .iso-file to see that it's roughly the same as the size of the old .mdf and .md0 combined.
If it's the same size as just one of the old files, double-check the renaming-process.
When successful, burn in Toast!
Hope I explained it well enough... I've had two successful tries out of two, so it looks like it's the way to go.
Good luck!
