This command will make a visual selection of the lines that have the same indent level or more as the current line.

:exe "normal V" | let temp_var=indent(line(".")) | while indent(line(".")+1) >= temp_var | exe "normal j" | endwhile

Comments

A slight modification, to select the area above the cursor position as well, and the whole thing wrapped in a function (and nmapped to <Space>):

function! SelectIndent ()
  let temp_var=indent(line("."))
  while indent(line(".")-1) >= temp_var
    exe "normal k"
  endwhile
  exe "normal V"
  while indent(line(".")+1) >= temp_var
    exe "normal j"
  endwhile
endfun
nmap <Space> :call SelectIndent()<CR>

Currently, I just set foldmethod=indent and select the folded area.