They look out all the time for people who could be useful in one way or another.

"They may turn out to be useful to us in some other way."

"I seem to remember having been useful to you in the past."

He is very well read, yet cannot see anything useful in his education.

Still, these people make themselves very useful in our society.

The idea had been around for a long time, but became useful in the 1600's.

You're here because some of you might be useful in that effort.

Some of them will be useful in the right places.

Which I'd say is less useful in fact than the little ones.

But that state of war was useful in other ways, as well.