I was able to find some in FX like :
http://fxtrade.oanda.com/analysis/open-position-ratios
http://www.tradingfloor.com/tools/fx-options-analytics-retail-positioning
http://www.tradingfloor.com/topics/forex-open-positions
http://www.dailyfx.com/technical_analysis/sentiment
Futures :
http://www.cftc.gov/MarketReports/CommitmentsofTraders/HistoricalViewable/cot122413
http://www.cmegroup.com/trading/interest-rates/cftc-tff/main.html
Please share other resources, perhaps in other asset classes, or sources of curated data.