Lefty,
I LOVE CETFs. Right now, I would hold off on any of them, as a lot of them are stopping the dividend. BIF is a prime example. What was a dividend paying stock for YEARS, has stopped paying dividends, and may do so permanently. A lot of these funds are having trouble meeting the Basic Maintenance Requirements, since their holdings are tanking so bad, so a lot more funds will soon be forced to stop the dividends. I see a lot more downward pressure on these funds, so if you do want to get into them, the best way is a slow accumulation through something like Sharebuilder.com, where you can buy a set dollar amount per week or month at a flat fee.
Overall, the market has nowhere to go but DOWN, but one day it will start the gradual climb back up. Guessing a bottom is a risky proposition in this market! (Heck, how many geniuses have said Citibank was a steal at $13.00, and look at it now!) I am accumulating some CETFs now by buying through Sharebuilder, in the knowledge that in the short term, I will probably not get any dividends, but down the road, when the dividends start back, I will be a happy camper.
Hope this helps!