One minor pet peeve I had with Vim has been resolved by this neat little trick. Commenting out multiple lines in Python has always been somewhat of a chore for me in Vim. Thankfully, it is actually quite easy:

• Hit Ctrl+V
• Select the lines you want to comment out (don’t use the mouse for that)
• Hit “0″ + “I” (capital i) to write simultaneously at the beginning of the selected lines
• type “#”
• Hit “ESC”

Update: it’s actually even easier (thank you to Tobi for pointing out this most elegant use case of search and replace in Vim):

• Hit Shift+V to select the lines you want to comment out.
• Enter “:s/^/#/g” to search and “replace” (in this case insert) # at the linestart.

Job’s done. One very neat little trick.