Although there are extensive long-distance bus routes connecting points within the province of Buenos Aires, limited options exist for travelers wishing to reach destinations by air. According to an article [in Spanish] on Mensajeroweb, all of that may be about to change. The provincial government of Buenos Aires announced an initiative that makes subsidies available for new flights from the capital to locations around the province.
On November 17th, Sol Líneas Aéreas began operating flights from Aeroparque "Jorge Newbery" to Tandil. The airline also proposed additional routes to Necochea and Villa Gesell, subject to a government feasibility study.
A direct flight from Buenos Aires to Necochea would definitely appeal to my family members coming to visit from the States. Let's face it—after almost 11 hours on a plane, the prospect of a 5 1/2-hour car ride or up to eight hours on a bus just isn't that exciting.
[Update: Although Sol Líneas Aéreas did operate flights to Necochea for a brief period of time, service was suspended indefinitely in March 2009. Regional carrier LAER now offers flights between Buenos Aires and Necochea.]