Till today if you wanted to grab your mail from other POP accounts, it required a journey into the settings menu to look for an obscure command and then twiddle your thumbs for a few minutes. No longer.
Today Gmail has released a Labs tool that places a simple "refresh" button in the Inbox view, next to the menus above the incoming mails. Clicking it starts the process and you can see a refresh logo and the text "Fetching mail...".
There have been a number of threads in the Google Support Forum requesting this feature from Google and they have finally delivered.
For all the anger directed towards Google, it is good to know that they do actually pay attention to the hue and cry of its users.
Official Gmail Blog: New in Labs: Refresh POP accounts