Zouheirn, don't stir a sh*t! Single entry visas for ALL "passports". Don't say nonsense.. Why out of ALL nationalities the exception would be made only for UK?
Citizens of 34 western countries can obtain a visa upon arrival, without prior application, but more or less the same rule applies to the entire world, not only in Qatar.
ravi.shock, in order to obtain a visit visa (only Single entry, like everyone!), you have to have relatives here, who can sponsor you. They should know the requirements. Otherwise you can apply through the Hotel.