NO. Upgrading using anything but Sony Official Firmware will violate the terms agreed upon in the EULA. Doing so will void your warrenty.
only on slim
Yes you can and the PS3 will upgrade them to near HD quality.
I am Pretty sure it will, As the slim is an upgrade form the lower 360 platform so as long as you have the update from xbox live you should be able to play doom 3 on the 360 slim
exercise
In order to get skype you need to upgrade your psp to at least 3.90(only for slim). The other psp I'm not sure of.
yes
No it cant.
upgrade your psp to 5.03 then get chickHEN R2 which will modify your psp. then go to http://pspslimhacks.com/ it will help you alot
By far the psp slim, it was the best psp of all with the lates technology without the latest updates.
They are sold with the controller
$299.99 without tax with tax its $338.98
The 360 slim isn't an upgrade, it's a new console release. You can however try gamestop or entertainmart and see if you can sell your old 360 to help split the difference for a used 360 slim, this is what I did when upgrading myself from original xbox to a 360 elite. Or you can sell your old 360 for as much as you can get for it without going over it's original price (or you can try ebay.com if your the appropriate age, that can help get a good price too and perhaps go over) Then use that profit for a new 360 slim.