Petawatt lasers are a new tool to understand many basic properties of matter (solids, plasmas, molecules, atoms, and nuclei) in extreme conditions. Radiation reaction and fundamental non-linear QED problems can also be studied with high intensity lasers, as well as many other relevant problems. In all cases we focus the laser to concentrate its energy over a small volume, therefore a huge intensity gradient appears, and it generates a force -the ponderomotive force- that drives the ionized electrons. This driving can be dominant in some situations. A conventional focus has a convex intensity pattern and ponderomotive force expels the electrons out of the focal region. With optimal use of TEM 01 and 10 modes it is possible to generate concave beams that trap and drag such electrons. Such possibilities are reviewed here, particularly for the strongly relativistic intensities available with existing ultraintense lasers.