Important paper the one that David Beard mentions at Archaeology in Europe:
Stephen J. Lycett, Understanding Ancient Hominin Dispersals Using Artefactual Data: A Phylogeographic Analysis of Acheulean Handaxes. PLoS ONE, 2009. (Open Access).
Lycett analyzes the structure of Acheulean handaxes of Africa and Eurasia and concludes that there is very strong support (>94% likelihood) for an out-of-Africa scenario.
In all maximum parsimony trees, Eurasian axes appear as derived from African ones, possibly indicating that a migration (H. erectus or H. ergaster, depending on your naming preferences) from Africa to Eurasia happened along that techno-cultural spread.
Acheulean was first developed in Africa, some 1.6 million years ago. The most ancient confirmed date for Eurasian Acheulean is that of 'Ubeidiya (Palestine), dated to c. 1.4 million years ago though often thought of as a penetration without further consquences, followed by European ones (southern Spain, c. 900,000 BP) and more recent ones (c. 780,000 BP) in Palestine and other European areas (c. 600,000 BP). South Asian Acheulean is less well dated but most findings seem to be older than 800,000 BP.
However in Lycett trees, South Asian handaxes' typology appears consistently as older than European one (but more recent than the African types). He does not seem to have analyzed the very old Iberian or Palestinian tools though.