I went looking for HFS/HFS+ undeletion tools for OS X and didn't find anything reasonable. PhotoRec is filesystem-independent: it will find files of many particular types as long as they are contiguous1 (and not on ReiserFS, which Mac people don't have to worry about). It promised to take several hours to scan her machine in FireWire target mode, but it went through the flash card the photos came from in 5 minutes, which turned out to be all we needed. 100% recovery.
PSA: If you're using a Mac, you really want to be using Time Machine.2 OS X filesystem undeletion is where DOS was fifteen years ago: if you want to undelete, you have to buy commercial software (before seeing if it works) or crippled "shareware" (after getting a demo of the form "I can recover these files for you if you pay up"), in both cases for about $100. Linux is in much better shape.3
Incidentally, I found PhotoRec after searching del.icio.us, which I only tried after Google searches turned up huge amounts of useless crap. Apparently the ungooglenet is still useful for something now and then.
1i.e., stored as single chunks on the disk, which is typical if they were created all at once like photos; files you create bit by bit, like text documents, may be "fragmented" into many little bits and not come back as well
2If you don't have Leopard, Jamie Zawinski's backup process is close enough.
3Not that relying on undelete is ever a good idea; but still, free operating systems completely win on availability of essential software applications.