No you have to keep putting the disc you can only play a saved game unless you have the game downloaded
This is to prevent people from renting games and installing them on their harddrive.
Buy your games from Steam at steamcommunity.com or from Direct2Drive.com. You can purchase and download your games instantly with these two programs. No disk required!
Some games require that the game disk be present in the drive to play. Other games do not require this. The only way to circumvent the need for the disk to be present is to go on the internet and search around for a cheat that will allow the game to be played without the disk.
In general, no. You need the game disk to play an Xbox360 game. Of course there are games you can buy through the online marketplace, and some of those are the same games you can buy on disk. Obviously for marketplace games, you won't need a disk. The Xbox360 does have an "Install Game" option once you've inserted the disk. However, you'll still need the disk to play. Once installed, the game is able to load some features faster, but it does not eliminate the need for the disk. The other topic to bring up is console modification. Through a risky not-for-beginners modification process, it's possible to enable the Xbox360 console to play the games you backed-up to hard drive, without the disk. Be warned that modifying your Xbox will void your warranty, and may get you banned from Xbox Live.
yes you can
Yes, you can play PSP games without a memory stick. However, if you're playing games from PSP UMD's (little PSP games in cases). If you want to play games saved in your PSP's hard drive, then no. So, pretty much by UMD, you can play games without a memory stick in your PSP, but you'll be unable to save.
no
yes
No you can not, you need the disk in order to play.
Yes, you can buy them from games on demand. The only thing you add to the HDD when you save a disk is it will read it from a damaged disk.
No you can play PS2 games and some PS titles only
Yes, just choose the disk channel, insert a game, and click start.