Can you update an iPod Touch 2nd Generation past i0S 4.2.1?
No there is absolutely no way to do this. The CPU isn't capable of a vial function. It can support ARC or automatic reference counting. This helped out programmers and became part of the OS. It was a lot of work to keep thing compatible and then (most likely to increase sales) apple temporarily removed the ability to do this. After that most app developers removed non ARC code and this causes the iPod not to get many app updates anymore as a result.
If I upgraded my second generation iPod Touch to iOS 4.0, how would I jailbreak it?
Limera1n jailbreaks 4.0. I would use that, since it is the easiest and you don't need to download or sign ipsw files. Whatever you choose to do, download TinyUmbrella and save your blobs with it, and then download ipswDownloader to download iOS 4 for the iPod touch. It will tell you the jailbreak methods available for the device. The 2G touch is very slow though, barely supports multitasking, and that feature can only be enabled by jailbreaking. I'd advise getting a 4G touch. If you jailbreak with PwnageTool, you can include the SBSettings, SSH, and Cydia bundles from the jailbreak tool side, and save yourself time for after the jailbreak. But if I were you, I'd just download limera1n. All of the other tools just use the limera1n exploit anyways.
Free call/text apps for iPod touch 2g (iOS 4.2.1?)?
Download textfree (the old one) and it should say "would you like to download a older version"
I have a jailbroken iPod touch 2G with iOS 4.2.1. Is there any way I can download Installous or any alternatives to Installous?
Installous disappeared. If there is not any other shop option available you will have to find each app individually and install it individually also.Although, maybe you would like to try Whited00r:iOS Community Custom FirmwareIt is really cool, great performance in old iDevices and also has a custom store with old apps on it.It is based in iOS3.1, which had the maximum performance on iPod Touch 2G and iPhone3G (the iOS4 was a full disaster for those devices, make them so slow as useless).
Does iOS 5.0.1 improve the battery life of the iPod Touch 4th generation?
YES. I at best had 4 hours for the last few weeks but now it's actually almost an entire day (which is better than any previous iPhone)
Games Compatible with iPod Touch 2g 4.2.1?
Any games compatible with iPod Touch 2g 4.2.1? there literally seems to not be anything.... I curreently only have flow free, fruit ninja free, and unblock me. my ipod is jailbroken ( as far as i'm aware installous doesnt work for anyone anymore) sooo any FREE games in the app store?