(SmartMoney) Not long ago, short-term bond funds were thought to be for cowards. They were boring, unimaginative and safe. Now some savvy investors are shopping for them—precisely because they’re considered boring, unimaginative and safe. Last year investors plowed more than $50 billion in new money into short-term bond funds, which typically invest in corporate debt maturing in less than five years. That’s more than 10 times the amount investors put into the funds in 2007, according to Morningstar.