You often have the choice of using either a browser-specific add-on/extension or a bookmarklet to perform the same function. In such cases, because I use multiple browsers (Chrome, Firefox, Safari, and IE) on both Mac and Windows machines, I almost always opt for the bookmarklet. Syncing bookmarks across my browsers (using Xmarks) means that once I've added a bookmarklet in any one browser, I now have access to that functionality in all my browsers. I don't have to try to locate add-ons for each browser (if any even exist) and install them individually.
Typically, a bookmarklet won't lose it's ability to function if your browser upgrades as can sometimes happen with add-ons. Adding a bookmarklet won't require a browser restart, either. Bookmarklets have a negligible effect on your browser's memory use since they are only executed on demand.
Bookmarklets are typically installed by dragging the bookmarklet onto your browser's link toolbar or by right-clicking the link, then clicking the bookmark option.
Here are links to some popular bookmarklets you might find useful ...
- Read It Later
- Google Notebook
- Blog This! (Blogger)
There are hundreds, perhaps thousands, of bookmarklets available for many uses. You might like to visit Collection of Google Bookmarklets for bookmarklets related to a number of Google services.