Knickers = Panties (although I have a note on this one that it's my assumption as I'd never heard of 'panties' before I came across nfic!)
This is true; however, you need to be careful with this one. Women wear panties. When you call men's underwear panties, it's usually intended as an insult, ie, to tell a man he's acting in a way usually associated negatively with women, ie, catty or bitchy. Such as "Don't get your panties in a wad."
Rubber = Eraser
This made me laugh, since rubber is a term for a condom in the US. You might get some odd looks if you called the thing on your pencil a rubber.
