Robert Bittlestone's "Odysseus Unbound" is a massive book, nearly 600 pages filled with excellent illustrations (maps, photographs, aerial photographs, satellite images) and a highly detailed narrative explaining the development of and evidence for the author's theory: that Homeric Age Ithaca, the kingdom of Odysseus, was not located on the modern island of Ithaki, but instead on the western peninsula of the nearby island of Cephalonia. The evidence presented is complex, involving literary sources, geology, and archaeology, but a critical portion of the author's argument is whether in Homeric times this western peninsula was separated from Cephalonia by a sea channel since closed up by earthquake-induced rockfalls.
Although Bittlestone is "only" an enthusiastic amateur, his research has been reviewed and backed by his professional co-authors, one a professor of Greek and Latin and the other a geologist specializing in the Ionian island area.
I find Bittlesone's analysis to be persuasive, but as yet -- and he recognizes this -- the evidence is not wholly conclusive. This may come in the next several years with additional geological work to confirm the existence of the sea channel and with archaeological surveys to study various associated sites.