when i used to go out early in the morning while it was still dark i used to carry an umbrella, because that is like a stick that you can hit someone with

Sting don't they? A place where i trained many years ago held a seminar in a hotel and as you know when using wooden 'chucks your sweat makes them slippy after a while. We broke two windows with them flying out of peoples hands.
What do you mean by a gaffiti set?

I note that most people on this post are out of the UK. Of course being an American we have different laws over here. However, as a note there is an important thing to remember regarding utilizing improvised weapons.

It could be a case that if you practice the use of improvised weapons, you know to be prepared for the possiblity, it could be said that your use of a improvised weapon that you may be carrying is actually premeditated in its use because you have practiced using it as a weapon.

I know American Lawyers are such a pain. But just a thought in case any UK Lawyers figure out that as an angle for prosecution.

So anyway, I have a loose curtain rail in my bedroom (metal, made from two interlocking pieces) so one half of that is my immediate weapon of choice in case of burglary.
In the study just across from my room is a machete I got from Peru (and use for gardening, honestly) but I probably wouldn't resort to that, since it's a bit over the top, and unwieldy, since its handle is an animal horn of some type and it's decorated with llama teeth. Does that count as improvised?
I hear a small Coke bottle (lid on) can be used quite well as a thrust weapon into soft targets like the throat, but how wieldy and effective it actually is compared to a fist I just don't know.

Re UK Law: A section whose number I forget of the Police And Criminal Evidence Act says you can totally arrest a crook if there are no police around to do it for you, so immobilise that scumbag and call the police.
Also, I believe the common law regarding self-defense includes defense of your property.

Ah a nice coke bottle. Its great and if you happend to have a full bottle, or at least half full, it makes a nice little impact weapon as well.

even if you defend yourself with a pen, you are defending yourself with something, and the law in the UK is if you use anything against your opponent it is considered a weapon, and weapon is such a big umbrella and nearly everything is considered a weapon by the law.

Also i keep change in my back pocket, that is also a good distraction to get it the first strike

Well if a burglar came into my house and I caught him he would find himself with a katana pointed at him. Granted it is totally blunt and weighted for training purposes and would do about as much damage as bashing him with a pole but he doesn't know that.

And something that I discovered that is so random yet totally works is that if you are being mugged or such, chew some gum then spit it at them. 90% of people will stop attacking and try to get the gum off them. Hello opportunanity.

Hold on, do you mean chew gum all the time, just in case, or try to stay slippery enough to get some gum out and chew it up before they managed to hurt you?
Additionally, all the gum I've ever chewed needs a pretty hefty force (compared to my spitting power) to get it to stick to anything much. Do you use a particularly gooey brand or do you just pick a special target, like their hair?

Hahaha, i'm glad that someone actually took that method seriously. I mean it in the context of doing something unorthodox. Catch them off guard with something totally out there.

i have a kubaton on me nearly always, are they legal in the UK to carry around?

i am going to get one of those kubatons