And the summer just keeps on getting better....

Yes, that is right! Another downgrader is in progress as we speak.
Yoshihiro, Mathieulh, and Dark_Alex are currently working on a downgrader that will allow you
to downgrade your 1.50 to a 1.0 PSP! This was the first firmware that made it onto the PSP, and
was only available on Japanese PSP's at launch. This first firmware was, and still is the only firmware
that will allow us to run unsigned eboot files without any exploits. Nem was the first to release a
homebrew application in the classic form of a "Hello World" application. The one benefit for this
downgrade is the ability to run unsigned eboots, and ultimately hacked firmware. This means that,
like the Undiluted Platinum modchip, we will be able to use custom firmware as our firmware.
This downgrader has been tested by FreePlay and Dark_Alex to work, so all looks promising!

Mathieulh, Yoshihiro, and Dark_Alex will be releasing this downgrader tomorrow if everything
goes to plan. We will inform you all when the downgrader comes out as fast as humanly possible.
In the time being, feel free to check out the talk as it happens in Fanjita's IRC channel.
You can access this by opening your IRC client, join the irc.dashhacks.com server and join the channel #noobz.

This looks very promising for those of us who don't want to cough up $100+ for the ability to use custom firmware. But a downside to it is the loss of battery life, but hopefully there will be a way to modify the firmware to run it at 222 MHz. I would love the idea of playing games that require firmware 2.6+ on my psp without having to sacrifice my entire 1 gig memory stick to load the ISO of it. This could turn into something great, but I wonder if it will be perfected by tomorrow, or will the infamous "brick" strike again? We'll just have to wait and find out! I just hope there is a decent way to implement a custom firmware using some sort of loader instead of updating the PSP to it, unless it will be or already is a possible concept of it. I'm hoping for the best!
----edit----
It's looking good, check out the video here, can't wait for some more progress (although I don't know if I will sacrifice my 1.5 for this, even though there will be the option for custom firmware, I've waited too long to get to 1.5 just to throw it away!!!)

idk, i really like my 1.5 since all the apps out there come ready for it. And i know theres gotta be a catch to this downgrader, like the mobo bs, 1.5 couldnt and has to have been upgraded and downgraded bs, or something like that but sounds cool. Just dont ill downgrade tho.

[Terdinglage]

1.5 is where it is at for now, let the devs take advantage of this new development.

yea ok, if they manage to make a custom 1.5 like with browser AND homebrew then ill definitly downgrade, and upgrade to that!

yep no matter what this is not just for having 1.0 lol its for a transition lol

on psp-hacks theres a download of smash g psp for 1.0... why would they have that if no one in america has had psp 1.0?

and custom firmwares sound cool if they could make one that allows 2.0+ games to run on it without DevHook and have hombrew that would be bad A$$