Pros:
1. yep, energy saving bulbs (CFL) are great replacement for those conventional (incandescent) lights you use frequently. normally the packaging of the energy saving bulb will state the equivalent incandescent light bulb it can replace.
for example, 60W - 15W means that the 15W CFL has the same brightness as a 60W incandescent bulb. this means a 400% reduction in energy consumption.
2. they run cooler than incandescent bulbs.
3. the last much longer than incandescents.
Cons:
1. dispose of all fluorescent tubes carefully. they contain small amount of mercury (a few mg), so be careful not to break them during disposal.
2. much more expensive. an equivalent incandescent lamp can cost less than $1 compared to CFLs that costs at least $5(??). so in terms of cost, for a seldom used lamp (eg storeroom or balcony lamp), a normal light bulb should be cheaper.
3. CFLs cannot be dimmed directly. altho there are now ballasts for CFLs that allow dimming...
just to add. the spirals in the lamp is to increase brightness i think. the longer the tube, the higher the light output. the spirals allow a longer tube to be squeezed into a small package.