how can i download apps that arnt in my app store on the android?

[oneonone]

i have an experia x10 and i try going onto the app store to download apps but they arnt there. so i go on my internet and download it there on my phone that clearly says its for the droid. then i try opening it and it says "for security, your phone is set to block installatiion of applications not sourced in the android market". then i looked it up and people say to get a apk installer so i did and i opened the download to install it and it said the exact same thing about it being not able to install it because of security reasons....is there any thing else i can do to get it on or a setting that i can change?

 

[ZombieMom]

Click on the menu button on your phone. Click on Settings. Click on Applications.
There should be a menu item called Unknown Sources (Checking the box will allow installation of NON-Market applications. You want to check this box. This will allow you to down load apps from other sources other than the Android App Market. But, for safety, I would un-check the box after you have done your download so that you don't get any accidental downloads that you don't want. And then just go back in and recheck the box when you do want to make another download this is not from the Android Market.