  We consider a simple method of generating solutions to Einstein gravity
coupled to a dilaton and a 2-form gauge potential in n dimensions, starting
from an arbitrary (n-m)-dimensional Ricci-flat metric with m commuting Killing
vectors. It essentially consists of a particular combination of coordinate
transformations and T-duality and is related to the so-called null Melvin
twists and TsT transformations. Examples obtained in this way include two
charged black strings in five dimensions and a finite action configuration in
three dimensions derived from empty flat space. The latter leads us to amend
the effective action by a specific boundary term required for it to admit
solutions with positive action. An extension of our method involving an
S-duality transformation that is applicable to four-dimensional seed metrics
produces further nontrivial solutions in five dimensions.
