Compact flourescent
bulbs last much longer than incandescents and consume
one-fourth the energy for the same light. The prices are
coming down steadily and you will quickly recoup your investment
in new bulbs.
They are available in various lengths and some are short
enough to fit in small globes.
Replace all your old bulbs. The only disadvantage is that
they turn on at about 80% brightness and take about a minute
to come up to full strength, but newer bulbs are
overcoming
that
small problem.