For the less geeky and those with children, there are a great many things to do in the area aside from walking, drinking and hacking. The following is a small list of local "attractions", most of which can be reached by car, public transport, or with a short, easy walk
There are pebble beaches at Combe Haven and Birling Gap.
The three most well-known are Bodiam, Arundel and Pevensey, all open to the public. Pevensey is particularly interesting, being built on the site of a Roman fort, and still shows traces of Roman stone-work, and was used as recently as the 1940s as part of the costal defences and as a barracks for Canadian troops. Herstmonceux "castle" is really a fortified mansion and not open to the public, but its gardens are. It was home to the Royal Observatory for forty years, between it moving out of Greenwich and then relocating to the Canary Islands. Arundel is a magnificent building which dominates the town, and also has a very good cricket pitch in the grounds.
If Sussex are playing any one day matches at home during the LBW, your correspondent will be delighted to take benighted foreigners along and attempt to explain the rules.
The hills around Alfriston are one of the best places in the country for hang-gliding, and there is at least one flying school nearby that offers lessons.
Both the Kent and East Sussex and the Bluebell railways are nearby.