Two solutions:
- Sign your applet. Thus it will be able to save files on the user's disk. Not everybody will trust your applet enough to give it these rights... So, reduced audience.
- Have a server-side script allowing to upload a file from the applet. The PostToWeb library eases this process. You need to be able to run a custom script (usually PHP) on your server.

I have the applet signed (and got the confirmation when I tried to run it) but it doesn't appear to be saving the frame to my computer anywhere that I can find (searching for it on my computer turned up nothing).

Just to confirm what I think you are saying:
saveFrame("someframename-####.jpg"); should work online without any extra work??

Well, perhaps it works, then it will probably save in some place depending on the system (OS) running the sketch...
You better use selectOutput() to ask the user where to save the file, thus not depend on the OS, and let them know where they save it. If you save repeatedly, ask only once to get the path, then use it to save all your frames.

Moderator's notes: Copy of a new, duplicate thread I deleted. I paste here the message (in black) to avoid loosing it. Violet sentences are mine.

//this is a repost, I think I posted in the wrong section originally and was unable to get an answer that works there so I'm hoping this is right

You are in the right section, I probably moved the thread from the Programming Questions. Questions about applets belong here. I deleted the duplicate thread... If you have trouble making it work, just continue on this thread.

So, I have a simple drawing applet (it is signed and all that good stuff) but I learned that just saveFrame doesn't appear to work for online use. I was hoping someone could help me be able to save a jpg of the "canvas" (or the entire thing) and either put it in the common downloads place of the user or ask the user where to save it. I haven't been able to figure this out :-(

Things that I've done/tried already:
 - The applet is signed and I do get the dialog box confirmation when running
 - I've tried setting a folder with selectFolder() (this doesnt appear to work at all for saveFrame or I'm doing it wrong, both computer and internet versions)

Just show your attempts, perhaps you made a base error.

 - I tried selectOutput() but that appear to save information to a file already made (like strings to a .txt and doesn't appear to be useful for saving an image like this)

Idem as above.

 - I have read everything I can find on save(), saveFrame(), selectXXX() and can't find anything that explains my goal so please don't just point me at those, if they are solutions please explain what to do with them :-(
 - I dont think I can save the image server side but if that is a possible solution I'd like to hear about it

I pointed to the PostToWeb library, search it on the forum, you will find lot of relevant threads.

I don't know what the heck just happened but I had a reply posted then it was suddenly gone so heres the short of it.

Just show your attempts, perhaps you made a base error.

  if(mousePressed && mouseX>=700 && mouseX<=755 && mouseY>=460 && mouseY<=500 && i==0){
    saveFrame("Drawing Project/Drawing-#####.jpg");
  }

So the goal in my head is the the user will click the word "Save" and it will save the jpg to their downloads or a place they select. Currently as a sketch it works for me but as an applet it is not appearing to do anything. It says on the saveFrame() page that it won't work without a signed certificate so I assumed it would work with one (it currently isnt). So I imagine I'm missing something extra that isn't described there or something.

I've also looked through the examples and tried that PostToWeb thing and it didn't work (I'm pretty certain its because I cant create the files on the FTP since it is hosted on my university's server)

I meant show the attempts with selectFolder, since you wrote you tried and failed to make it work. We already saw that saveFrame alone won't work well.
The saveFrame you show will just attempt to write the jpg file in a "Drawing Project" folder that just doesn't exists wherever the system attempts to write, so it will silently fail.

" I had a reply posted then it was suddenly gone"
It wasn't a reply, it was a new thread, and since it was an exact duplicate of this one, I just deleted it: no need to dilute efforts of those willing to help. I kept your message because it added information to this thread. Actually, I made it a real reply...

errr, I understood what happened to the other post, I meant I had a reply to this thread with more stuff but it somehow just was gone when I came back to the topic. Dunno what happened

I'll try to set up the selectFolder thing again later but when I run the sketch itself the Drawing Project folder is created when the save button is pressed with the images then placed inside so I was trying to do the same with applet version

Yes, but an applet has no "sketch folder" where to create folders and images. If one is created, it can be in the user's home dir, in a temp dir, in the temporary internet files of your browser, or any other location the browser / Java combination can come with...