If you are surfing the Internet on a PC, bookmarklets save a huge lot of time to do stuff. Click them on the Bookmarks bar and the work is done.
Below are my few hand-crafted bookmarklets. Just drag the link (bold text) to the Bookmarks bar to have it there.
This list is not complete (and will never be). New ones may be added from time to time as I make them.
Also, you can directly try them out by clicking on the links.
Get QR code of the current web page
This uses Google chart API to generate QR code for the current URL, so that you can share it or let another one scan it using their smartphone.
Look up on Wikipedia (English)
Select an English word or phrase that you want to know about, then click the bookmarklet to look it up on the English Wikipedia.
By clicking the bookmarklet, the whole page will be set to be editable. That means you can click anywhere and start typing. It’s time to go fake something! >:)
Note: When the page is in editing mode, links can’t be clicked, so you should drag “Stop editing” to the Bookmarks bar before you press “Edit”. If you haven’t, you can refresh the page (which reverts everything you’ve made).