wordpress:

• akismet: finally, a widget to properly manage comment spam with.
• comment timeout:the second arrow against spam - i close comments after a couple of weeks.
• tiger administration: provides a slick interface makeover for the wordpress dashboard.

firefox:

• fireftp - lets you ftp from within firefox. this makes life so much easier.
• firebug - which is very very useful for playing with css markup directly within firefox.