How do I beat the solo development blues?
lux: Use Cake to build an app that you can sell online as a service.  If the service takes off, there's all kinds of opportunity for learning as it grows and technical requirements change (scalability, security, etc).I've been doing client work in my one company for years (7 to be exact) and while it's an okay model for making a living, the revenue is connected with the hours you put in, which to be honest sucks.  It means you can grow by adding people or becoming a bit more efficient, but neither of those allows for exponential growth.  As such, it's not the right model for startups.Instead, you want something where you make residual income every month off something like subscriptions.  With that type of model, you make steady income (if you can sell it) and there's the potential for exponential growth without exponentially increasing the number of people involved.As for ideas, most software you can write that you install on your own server (Cake type stuff) can be made as an on-demand service as well.  And most jobs that are done in a consultancy can also benefit from software to make those jobs more efficient.  I say pick one and go for it!