Some mozila firefox add-ons
1 - AnyColor :
This add-on can change the style of firefox to any color you choose .
2 - TinyURL Generator :
this add-on give you the possibility of to short the link of the website u visiting by clicking on a small icon in the bottom of mozila firefox .
3 - Adblock Plus
Maybe some websites make you angry cause the maker of them place the adverts on the middle of site page , the solution is adding this add-on to remove those adverts . Its will really change the look of annoying websites .