I'd have to agree with those who prefer slightly higher resolution displays. All my systems have native 1920x1200 heads: htpc, work laptop and home laptop. Although, at work I use two 1920x1200 24" panels for a spanned desktop.
On the original topic of FF add-ons, I'd like to suggest
FoxyProxy. I use it at work to proxify my "personal" browsing through a socks proxy (dynamic port forwarding SSH tunnel), including DNS lookups. You can set up URL whitelists / blacklists to decide which tunnel to use seamlessly. Keeps the IT nazis off my back.