This isn't an exhaustive list, just a list of some interesting, well known, lesser known, and cool stuff you can find on the Internet.
Need a throwaway e-mail address? Try chatsalot77 at yahoo dot com
Have an image but want to know where it's from? Try tineye.com
Need to convert a video into something else? Try benderconverter.com
Want to combine your PDFs into a single PDF? Try pdfsam.org
Have a video but just want the audio? Try aoamedia.com/audioextractor.htm
Want to change a GIF? Or make a GIF? Try gimp.org
Unsure if a site has malicious content on it? Try mywot.com
Want to see who owns a site and where it's hosted? Try whois.net
Need a rimshot right this instance? Try instantrimshot.com
Want to make a video game but lack the skills? Try yoyogames.com
Looking for a video game manual? Try replacementdocs.com
How about remixed video game music? Try ocremix.org
Where are the old sites? How to find dead pages? Try archive.org
What's happening in the world? Try news.google.com
Want to translate a foreign word? Try translate.google.com
Need to read music? Try datadragon.com/education/reading
How do you learn to do stuff online? Try howstuffworks.com
What are "hot keys", and where are they? Try keyxl.com
Itching to use your art skills for evangelization? Try oekakicentral.com
Where do knowledge junkies get their fix? Try mentalfloss.com
Need some wisdom? Try catholicbible101.com/quotesfromthesaints.htm
Where to read the Divine Office online? Try divineoffice.org
Where to read the Horologion online? Try orthodox.seasidehosting.st
Want to watch Vatican and papal events? Try vatican.va/video
Not sure if a Church document is online? Try vatican.va/offices/index.htm
Looking for more Vatican websites? Try vatican.va/siti_va/index_va_en.htm
What clergy belong to your diocese? Try catholic-hierarchy.org
What time is Holy Mass? Try masstimes.org
Where to read the Church Fathers? Try newadvent.org/fathers
What heresies did the Fathers fight? Try gbgm-umc.org/umw/bible/heresies.stm
Where to find excerpts from the Fathers? Try staycatholic.com/early_church_fathers.htm
Who are the Doctors of the Church? Try doctorsofthecatholicchurch.com
Who are the Martyrs of the Church? Try catholic.org/saints/martyr.php
Who are some Virgins of the Church? Try catholic-saints.info/saint-of-the-day/female-catholic-saints.htm
Who are some of the youngest saints in the Church? Try saints.sqpn.com/saints-who-died-as-children
Where to find the patron saint of that? Try catholic-forum.com/saints/patron00.htm
Want to read Catholic e-books? Try freecatholicebooks.com
Need to learn more about Jesus? Try thesacredpage.com
