Tools for designing a program

Hi
What tools are available for designing a program? Like paper(sketch on a paper).vym(mindmap tool) e.t.c.

Dia will do the job.

One of these might help: http://en.wikipedia.org/wiki/List_of_UML_tools
If I should recommend one I would say "Enterprise Architect". But it is commercial, though it is very cheap compared to others.