I dont have enough space to store my iPhone apps on my PC, so is there any way I can store it online and make iTunes sync with it?
Iphone doesnt support IOS 5 what now ? :(
Have you upgraded to ios5 ? which OS version are you using currently on your iphone?
You don't need iOS 5 and you don't need the iCloud.
If you don't need the App at the moment simply delete it from your computer/device. Purchases are stored to your Apple ID and as long as you are using the same Apple ID you can redownload previously purchased apps free of charge.
You can delete the app you don't need right now or don't regularly use , and re-download from i-cloud, without purchasing again if ti is a paid app.
Perhaps not exactly what you want, but you can free some space by doing this.