Since they tend to go down in value and are next to impossible to move, you might be better off renting until you can afford your own place (condo or house).
From Labor Day to Super Bowl Sunday, there are always great real estate bargins because the only people who tend to sell during that time of the year are people that NEED to sell. Since the pattern repeats every year, when you're ready, you could probably get a sweet deal. The way this mortagage crisis seems to be going, prices in South Bay will probably be soft for awhile (meaning you don't have to be in a big rush). Prices in the Central Valley will be even softer (drive a lot, save a lot).
A mobile home might make sense if it was on a vacant lot that you also owned. That way, you'd get the appreciation of the increase in the land.
Best of luck,
Roy