KINGSTON, Jamaica - Describing for a friend my impressions of the Guyanese economy after a brief visit, I simply exclaimed: the economy is bubbling. The observant traveller needs no recourse to gross domestic product numbers, growth rates, bauxite, rice, rum production or foreign-exchange rates. The hustle and bustle is evident any day but Sunday in Georgetown, the country's capital. It is evident as well, should one do a sampling of road, boat or air treks, arriving at any of the smaller towns linked to mining, forestry, fledgling ecotourism and transportation across the big rivers: Berbice, Demerara and Essequibo.