Visas are required by all nationals except those of Malta and Arab countries.
These can either be obtained from your home country at the the port and airport of arrival.
If traveling overland visas can be obtained from neighboring countries without much of a problem.
You can apply for either a single entry visa which entitles the holder to a stay of up to one month and is valid for presentation for up to three months, or you can apply for a multiple entry visa which is limited for up to three visits.
You cannot get a visa at the Israeli border.