4Kids Entertainment, which is battling toy giant Hasbro for 'toy DVD' market, announced its Game Boy Advance-TV system at the E3 show in Los Angeles this week.  The GBA-TV system uses plastic cartridges, each of which contains two episodes of a 4Kids property such as Pokemon or Yu-Gi-Oh!, that can be inserted into the Game Boy player in exactly the same manner as a regular game cartridge.  4Kids' GBA-TV system will compete directly with Tiger Electronics' (Hasbro) VideoNow player.  VideoNow requires kids to purchase a player ($49.95 srp), which isn't the case with 4Kids system, since many kids already have Game Boys.  And the VideoNow system programming, which consists of highly rated Nickelodeon shows like Spongebob Squarepants, Jimmy Neutron, and The Fairly Odd Parents, is all in black-and-white, while GBA-TV will be in full color.  The Hasbro system has an advantage in software pricing since it will sell 3-episode packs for $14.99, while cartridges for the GBA-TV are expected to retail for just under $20.