As everyone's saying, a good reason to keep the monarchy is tourism- we do get a lot of tourism revenue, and they don't require that much upkeep anyway. They also provide there own share of entertainment for the British people. Prince Harry landing an RAF helicopter in his gf's back garden, the whole Charles, Diana and Camellia thing, Prince Philip the dirty old racist, and the Queen, who is probably one of the best behaved monarchs we have ever had.
Here's an exhample from Mock the Week- http://www.youtube.com/watch?v=4CHB2CVgQws
They don't wield any real power, but i suppose if they wanted to act in a dire emergency (Like let's say the BNP take over undemocratically) if i where King i would be very tempted to refuse Nick Griffin office and use my army to perform a military coup.
After all, the British Army is not part of the British Government, it owes it's loyalty to the Monarch,which is why all our ships are titled HMS.
However, i think the best reason to keep the monarchy is because of the British national identity. The monarchy sits proudly among all things that are British- tea, crumpets, red telephone and post boxes, London taxi's, sleepy rural villages, Winston Churchill, rainy days, and the satisfying sound of a spitfire flying high above the white cliffs of Dover.
Oh, and not forgetting Top Gear and Mock the Week.
