No more Iphone 3G updates

I have an Iphone 3G (I know, it's not cool, it's not even retro cool). I have been using it quite happily for a couple of years now, updating the software, downloading new apps. Increasingly some apps haven't worked on the phone, and I just lived with this, although it was slightly annoying.

Recently, no new apps will download onto my phone. Apple have decided to scrap the Iphone 3G and concerntrate on the newer models.

Now I understand that at some point, things have to move. Unfortunately, with my iPhone still working, I think this is a sneaky tactic of Apple. I am now forced to either use my iPhone as it is, with no new features in the future, or get a new iPhone. It's forcing customers to spend more money on a new iPhone, and it's not very environmentally friendly.  I just feel a little disappointed that I am being left behind when my phone still works, and I have been a loyal Apple customer. If I buy an iPhone 4 to replace my phone, how long before that becomes too old? Am I constantly going to be forced to upgrade? I can't afford an iPhone 5.

So should I upgrade? My phone does everything a phone should do. It calls, it texts, saves contacts, and plays old apps. I love getting new apps and playing the new games and I feel like that's the main reason to have an iPhone. It's not great for calls, the sound quality is poor, and the touchscreen is horrid to write texts on. Is it worth the hundreds of pounds required to upgrade?

What phone do you use? Are you always trying to have the latest phone?