This chart is for the past 7 days:

Interesting to see how even though it looks like BTC is crushing LTC trendwise, it's actually getting just under 10X the amount of interest, while it remains over 20X the price.
PPCoin is on the scoreboard this week for the first time with 1/68th (1.47%) the amount of interest as bitcoin, while it's trading at 400 times less than BTC!
Conclusion, LTC and PPC may be significantly undervalued.