There's a lot of free WiFi in Brighton, mostly in pubs but the whole beach is also theoretically one big hotspot thanks to the wittily-named Pier to Pier network.
Central WiFi pubs include:
Grand Central (right by the station),
The Earth and Stars,
Riki Tik,
The 3 Jolly Butchers
and more. Also, the pavilion gardens, where the dome is situated, has free WiFi.
Be sure to check out E-Kagen in Brighton's North Laine area. It's a great spot for a hearty lunch of soba noodles or sushi. And the gyoza kick ass. It's open every day except Mondays, as far as I know.
