There are some really attractive an inexpensive solar lighting things available. They are kind of like torches, in that they are on spikes and can be moved to where in the garden you want them, and then stay there or be moved. I think they nomally give about seven hours of light.
I use old jam jars with nightlights n them for al fresco though. I know its not the safest option but its the most attractive, imo. You can use clear glass with white candles, or with bright coloured ones. If I had kids around I would get some glass paint and have them brightly paint the jars. If its not to dry you can make LONG hangles for the jar out f wire and suspend them from tree branches, but if its dry this is obviously a fire risk.