Another fantastic thing about mozilla (I don't think you can do this in IE but then i don't use it much so maybe you can), is the ability to assign keywords to bookmarks.

So for example you can create a bookmark to
http://www.multimap.com/map/browse.cgi?client=public&db=pc&addr1=&client=public&Submit.x=0&addr2=&advanced=&Submit.y=0&addr3=&pc=%s
with the keyword 'map'

and then just type 'map EH1 2AB' into the location bar and up pops a map of the area.

i've also done this for dictionary lookups, bugzilla bugs, MS KB articles - it's so handy:

adict: http://www.dictionary.com/cgi-bin/dict.pl?term=%s
g: http://www.google.com/search?q=%s
dict: http://www.chambersharrap.co.uk/chambers/chref/chref.py/main?query=%s&title=21st
kb: http://support.microsoft.com/default.aspx?scid=KB;EN-UK;%s