Contributed by B@rt.
Select the deformed object and press CTRL+SHIFT+A to apply the lattice deformation. You can now remove the lattice and the deformation will be stored in the object.
Contributed by B@rt.
To use a lattice, make it the parent of the object that you want to deform (select object, hold down SHIFT, select lattice, press CTRL+P).
You can change the resolution of the lattice in the Edit Buttons window (F9).
Contributed by B@rt.
In older versions of Blender, the resulting mesh would be deformed again by the lattice. Unparent the lattice (select the mesh and press ALT+P) to fix this.
Alternative solution: get the latest Blender version from https://www.blender.nl/download
2nd alternative solution: select the mesh and press TAB twice to enter and leave editmode.
Contributed by Rak.
In the recent versions of blender, when you apply the latice deform, it deforms the lattice. However, since the lattice is still in place, the mesh is deformed again, from the state it was just deformed to.
To fix the problem, either delete the lattice or clear the parent relationship with alt+p, and press tab twice (to go into edit mode, then out of edit mode).