Ghana Visa

Anyone know if a Ghana visa-on-arrival is available if arriving at Accra international airport? If not (or if it's a risk to count on it), can I get a Ghana visa in the following countries: Tanzania, Ethiopia, Egypt or Israel? I'm from Canada going on a RTW trip that will take me to Ghana more than 6 months after I depart Canada (hence I can't get it at home). Ghana looks awesome but I just can't wrap my brain around how I can get this visa!