Wolf, it depends on how you define waste of time. First, the low-limit mid-week Vegas games tend to be tougher than those in California, and I'd avoid those. But Vegas weekends, and California anytime, low-limit games can be taken, because there are so many (usually about six in a ten-handed game) bad players. The rake can be high, but the mistakes that are made more than make up for the drop.

Just remember that you will take some pretty heavy swings in these games, especially if you are an agressive player. These games are beat by playing a TAG style. I'd recommend reading Lee Jones' Winnning Low Limit Hold'Em to refine your play for $4-8 and lower. It's outstanding for taking on these games.

Best of luck.