It's another slow week on the DVD front, as we wander the desert of box office misfits, duds and bombs. First off is 'Skyline,' an interesting and actually well-conceived and -executed sci-fi invasion flick that was sorely hurt by a lack of a big-name cast and a close proximity to 2008's 'Cloverfield.' Next up is the much ballyhooed teaming of Angelina Jolie and Johnny Depp in 'The Tourist,' a comedy-spy thriller short on both laughs and thrills. And finally, there's 'How Do You Know,' a mangled up mess of a rom-com with a fine cast (Reese Witherspoon, Owen Wilson and Paul Rudd) and director (James L. Brooks, 'Terms of Endearment,' 'Broadcast News') that just doesn't have a life of its own. Read on.