How to descale an electric kettle?

Vinegar works great, fast and super easy!  Just pour in distilled white vinegar (about 35p a bottle at Tesco, much cheaper in a big bottle from Booker- catering wholesale chain) to cover the limescale.  Leave it sit about 30 minutes - no boiling necessary - boiling vinegar smells nasty!  Then just a quick swish with a bottle brush inside, a double rinse with water and all clean, all done. 

Of course the best way to avoid limescale (and to save energy) is to only boil the amount of water you need (fill tea cup from tap then pour into kettle) and tip out the kettle after you've filled your cup.  If there isn't water standing in the kettle, it doesn't accumulate lime scale for ages.

There is also a product called OUST all purpose descaler. It descales kettle,irons,coffee makers & shower heads. You just fill  your kettle half way and boil. Unplug  your kettle and place in a empty sink..slowly add the pack of OUST into kettle and leave for 10 minutes. Pour the solution away,rinse throughly with cold water..boil again with clean water ..empty and rinse throughly and its ready to use again,all clean. You can find OUST in any grocery store.

People could do the Kim and Aggie method of descaling taps on their kettle if they have the time and vinegar or lemon juice isn't working: Cover the bottom of an empty kettle with vinegar or juice, drench a few paper towels and stick them to the sides (inside) and spout (remove filter if your kettle has one and soak in a cup with some vinegar or lemon juice), cover with a carrier bag and leave over night, rinse well in the morning.

The paper towel/loo roll soaked in vinegar or lemon juice and covered with carrier bags/plastic really works on taps or shower nozzles. 

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Trying to visualize this:
Papertowel/loo roll soaked in vinegar or lemon juice, placed over the shower head and covered with plastic bags actually works?
My husband is constantly having to clean the shower head (or it seems that way).
We end up just placing the shower head in a plastic bowl, what have you, and soaking overnight in chemical descaler.

I live on the south coast where we have very hard water. 
I use Brita filtered water in my kettle and that really cuts down on the amount of descaling I need to do. 

?
Trying to visualize this:
Papertowel/loo roll soaked in vinegar or lemon juice, placed over the shower head and covered with plastic bags actually works?
My husband is constantly having to clean the shower head (or it seems that way).
We end up just placing the shower head in a plastic bowl, what have you, and soaking overnight in chemical descaler.

I missed this somehow.  

Yes it works.  Faucets, unlike shower heads, do not lend themselves to easy soaking in bowls.  I also soak my showerhead in a bowl with vinegar or lemon juice overnight a couple of times a year.  Both vinegar and full strength lemon juice work as well as any concoction you get from the store.  Some of the "chemical" descalers you get are pretty much the same thing that's in citrus juice anyway.  

ETA: Kim and Aggie use vinegar or lemon juice to descale things a lot on "How Clean Is Your House" if you need help visualizing it.

An article on using vinegar or citrus juice to remove limescale:

http://www.guardian.co.uk/lifeandstyle/2009/aug/23/how-to-remove-limescale

oh WOOWWWWWW... ahaha, that's what that is...

yesterday i looked in there and was like ewwwwe.. wtf.. and i said, baaaaaaabe, i think its time for a new whatchamacallit. LOL

i cleaned it as best i could but good to know its not just old. that i can clean it w/ ur guys suggestions. thanks!

lol too funny