Be careful while installing greasemonkey scripts

I would recommend you to view the source code before you install any greasemonkey scripts in your browser.
If you are not familiar with javascript, look if the script has the following words (do an Ctrl+F) :
1) "GM_xmlhttpRequest" (this can potentially send your data to third party servers!)
2) "document.cookie" or "cookie" (do not allow third party scripts to access/steal your cookie)
3) "script.src" (script src hacks can do much harm)

Though these are not exhaustive, they cover the majority of potential vulnerabilities. If in doubt, better not install the script.

Set reminders in GMail

G-Alert ^alpha -- A Greasemonkey script for setting reminders in GMail

WHAT IS IT ?

G-alert is a small script that runs on your browser when you open GMail.
You can select and set alerts on the mails that you need to be reminded later on.
It remembers the alerts set by you and pops-up a window on the scheduled time.

INSTALLATION

1) Install greasemonkey firefox extension https://addons.mozilla.org/en-US/firefox/addon/748
2) Install G-alert by clicking here.
3) Open GMail; you should now get a G-alert menu bar at the top-right of the window :

WHAT CAN I DO WITH IT?

1) You can set reminder alerts by selecting your mails, setting the time, and hitting the "Go" button :

2) You can add notes by clicking on "Add note". After typing out the note, you can set the time and hit "Go" to set the reminder :

3) You can view your reminders by clicking on the "View" button :

4) You can modify your reminders by clicking on the "Edit" link. After modifying the alert, click "Done" to set the new reminder :

NOTES

1) G-alert is in alpha stage, it has a few small bugs in it (if you find them annoying, please mail me or post in comments section).
2) This script does not send any data outside your computer. It does not do any server calls.
All data is stored in your local machine only.
3) Reminders are persistent and are available even if you restart your browser or the operating system.
4) It can be used with multiple instances of GMail.
5) Reminders open up in a new window :

If your browser does not allow pop-ups, you might need to disable the pop-up blocker (disable only for GMail).

Feedback : g.alert.scriptgmail.com or post directly in the comments section.

Coming soon : G-alert tricks and hacks