Depends on what you mean by "relative strength". If you're looking for a number a la IBD, then no. But if you're looking for sector strength relative to each other, go to stockcharts.com, click Free Charts, then CandleGlance Charts, then S&P Select Sector SPDRS. When that loads, select One Year and click Go, and you'll get something like this: http://stockcharts.com/candleglance/?XLF,XLK,XLI,XLB,XLE,XLP,XLV,XLU,XLY|D
It doesn't take a great deal of chart-reading acumen to see that Financials and Technlogy are in deep caca and that the stars among these are Utilities, Materials, and Energy (if you want to limit yourself to the last two to three months, you'll note that Energy takes the prize). You'll also note that Industrials recently failed to make a new high, which bears watching.
As for the industries and groups, you can do much the same thing using the MW link provided earlier, though you may prefer to go directly to BigCharts.com (MW bought them during the internet fallout). You can avoid most of the ads and promos this way. If you're interested, I'll explain how.