Depends on the bank. For my ccb account I think I can view my internet banking on any operating system but to make transactions I need to use a usb key that only works with windows and internet explorer.

At the moment I usually run linux, but I keep a windows partition on my computer mainly for this purpose. On a mac you can either install windows inside a virtual machine using software like virtualpc or you can use bootcamp to install windows as a second operating system. I'm not sure if the virtual machine will be able to access the usb key properly but it might be worth a try.

Any solutions for this? I am in the same situation; want to change banks, but strongly prefer one with English-language online banking that can run on a Mac.