Another poster suggested installing the application in Windows and copying it over to the Wine C:\Program Files manually. This worked! Installing PicoScope 5 in wine did not work. Instead, I installed PicoScope 5.21.1 in Windows XP in a VMware VM and tested that the scope worked in the VM. Then, I copied the "Pico Technology" folder from "Program Files" to the "Program Files" folder in my wine 1.0 installation.
Here's what I used:
Ubuntu Maverick 10.10 32-bit
Linux Driver R126.96.36.199.1 32-bit
Finally, in the wine settings, you need to create a profile for psw32.exe, which sets the OS to Windows 98 and add a DLL override for ps3000 (use builtin, not native).