Ilheu do Rei - a nice get-away for a picnic if you're in Bissau on a longer term. Go to Porto Canoa behind Mavegro and the cemetery and ask around for a canoa to take you to the island, it takes about 10 minutes and you should not pay much for the return ticket 1000 FCFA?. Once there, check out the abandoned peanut oil factory, and continue through the little village down to a little "beach" ask people where it is, from where you can turn left and walk along the coast, if you don't mind climbing a little over trees and rocks. For once there is no mangrove, so you can actually get the feeling of strolling along the coast.
Volta de Bissau Starting at the Porto Canoa, this track goes around Bissau, passing rice fields and small suburbs, the big cemetery in Antula, SÃ£o Paulo etc, and eventually you'll end up at the airport road close to Hotel Bissau Palace. A nice sunday walk, some 4 hours, not all stretches are suitable for vehicles.
Hotel Marazul (http://www.marazulpeche.com), in Quinhamel. Makes a fine daytrip for swimming and lunch, and maybe a fishing trip. In the town of Quinhamel there's also an interesting weavery, "Artissal" (http://www.artissal.org/), producing handwoven textiles.
Hotel Rural de Uaque (http://www.hotelruraldeua...) is also recommendable, if you need to escape from Bissau for a day, swim and relax.
Praia Suro in Prabis is the Guineans favorite weekend get-away in the dry season. The beach is a bit muddy, but there's always good ambient with music, people dancing, barbecuing, playing football and swimming. Just follow Estrada de Bor out of Bissau, continue when it turns into a dirt road, and eventually you'll reach the beach might be a two-hour drive.
Saltinho Waterfall - A pleasant little waterfall located just under the bridge where the main road to southern Guinea-Bissau crosses the Rio Corubal. There is a hotel "Pousada do Saltinho" overlooking the waterfalls, with decent rooms FCFA 20.000 and meals. Many Portuguese hunters and fishermen stay there. About three hours drive from Bissau.