Thanks for the info Kaito! I'm also wondering if it's worth upgrading my point and shoot camera if I get the Olloclip and Camera+? I want photo quality close to dslr camera... so maybe a ~$300 point and shoot? or even an entry level dslr..
Also, what do you think of the flash on the iphone 4S?
I would go the dSLR route if you are set on an iPhone and want a secondary camera. That way you can get interchangeable lenses, real depth of field, and more manual control. Like I said, I was going to get a Canon PowerShot S100 (the new one) because it had nearly all the features I wanted in a point & shoot, but the quality of the 4S just blew me away, plus the convenience of on-camera editing & posting (and free iCloud backup) is unparalleled - no computer required to do stuff with the photos! And with an Olloclip, you always have a lens system in your pocket to play with, which is really nice.
If you can, I'd save up and get the Canon T3i ($659 body). I have the last-gen model, the T2i (T3i adds a swivel screen) and it's just phenomenal. It's compact for an SLR, it does wonderful low-light, it supports flashes (like multiple remote flashes for Strobist with wireless triggers), it can take crop & full-frame lenses and pretty much any other brand of lens via adapters. Alternatively, the new Canon PowerShot S100 ($429) is the point & shoot I'd recommend if you want something close to a dSLR in a pocket-sized format. Both are a bit higher than your $300 budget, but I think the iPhone 4S would overlap most functions on a cheaper camera, you know?
If you want to get more into photography (not sure where you're at now skill/knowledge-wise), I'd recommend checking out the classic "Understanding Exposure" book by Bryan Peterson. It's fairly short but a bit complex; it's the best introduction to getting into manual photography I've come across:
http://www.amazon.com/Understanding-...dp/0817439390/
Also the Strobist website is an excellent resource to start learning flash photography from: (you can use multiple flashes with Alien Bee or Pocket Wizard-style remote triggers)
http://strobist.blogspot.com/2006/02/welcome-to-strobist.html
As far as the flash on the 4S - well, it's better than nothing. I'm not a big fan of on-camera flashes, although it's actually really handy on a phone when you just want to snap a quick pic and it's dark.