The Multiwavelength Approach to Unidentified Gamma-Ray Sources -- Regular Particle Acceleration in Relativistic Jets -- The Converter Mechanism of Particle Acceleration and its Applications to the Unidentified EGRET Sources -- An Examination of Candidate AGN Counterparts to Unidentified EGRET Sources -- A Search for TeV Emission from X-Ray Selected AGN with Milagro -- Beaming Effects in GRBs an…