With interest rates on the rise — and expected to climb even higher— plain-old cash is looking more alluring to savers and conservative investors.A savings account stashed with cash was the place to be for people who wanted to sleep at night during the 2008 financial crisis. Its value held steady while the stock market crashed — losing more than half its value — and home prices collapsed.But it quickly fell out of favor when the Federal Reserve cut interest rates to zero to make borrowing cheaper and revive the U.S. economy. While pushing rates to historic lows gave stocks, real estate and other risky assets a steroid-like performance boost, it amounted to a death sentence for cash and certificates of deposit.The reason: It caused the interest payouts on cash to virtually disappear, hurting savers, conservative investors and retirees who relied on income from their savings.But cash returns are inching higher again and becoming more attractive as the Fed moves to return rates to historically normal levels. At its next meeting on June 13, the Fed is likely to hike rates for the second time this year and boost its key borrowing rate to 2%, up from 0% back in late 2008. And Wall Street sees more hikes this year and next, pushing up the central bank’s key rate to an even more attractive 3%. That’s not to say savers will make a killing if they invest in cash or CDs, however.“Interest rates are heading in the right direction for savers — but you have to know where to look to get the highest yields,” says Greg McBride, chief financial analyst at Bankrate.com, a site that tracks the highest-yielding deals offered by banks and other financial institutions.