I posted a thread over at Amibay a year or so ago with my experiences using SDHC cards as IDE replacements with some basic benchmarks. The adapter I used was more or less the same as the one fgh linked to.
If memory serves me correctly, using Sysinfo on my 030 A1200, I would see around 2 megabytes a sec with a CF card where as with the SDHC card and adapter it was roughly 1.8 megs a sec.
Plus none of the CF compatibility issues some people report...especially with ACA accelerators.
Ahhh...here is a webcache of my post on Amibay:
http://webcache.googleusercontent.co...&ct=clnk&gl=us
Lots of good info in that thread. I would love to use the same adapter and card on an A1200 that has something like one of the Fast ATA interfaces.