Just because everyone's already mentioned the easy (and probably best) answer of just selling stuff you don't need, let me add something a little different:
Enter programming competitions, app hackathons, that sort of thing. The kind that are typically one whole 24h day, or perhaps an entire weekend, and offer decent prizes to the top few teams.
Now, I'll grant you that this might not be suitable for a number of reasons. The main one being that you sound like you need this money ASAP and perhaps there simply aren't any good contests this weekend. However, they certainly meet your criteria for being earned "in a relatively short time frame" since you're not working more than a few days and potentially collecting a 4+ figure check. You also (obviously) need some solid chops, but you mentioned that you're "very competent" at web and mobile development, and those are the hottest areas so that's a good start.
Some random examples of contests and competitions that I've been involved with recently include Mozilla Ignite [1], The Great Canadian Appathon [2], and a bunch of other low-key contests with smaller payoffs, often aimed at students. I'm linking to the prize pages just to show you that it can be very lucrative :).
So get out there and give it a shot. At worst you make no money but meet a bunch of awesome people, and they usually present opportunities of their own.
Enter programming competitions, app hackathons, that sort of thing. The kind that are typically one whole 24h day, or perhaps an entire weekend, and offer decent prizes to the top few teams.
Now, I'll grant you that this might not be suitable for a number of reasons. The main one being that you sound like you need this money ASAP and perhaps there simply aren't any good contests this weekend. However, they certainly meet your criteria for being earned "in a relatively short time frame" since you're not working more than a few days and potentially collecting a 4+ figure check. You also (obviously) need some solid chops, but you mentioned that you're "very competent" at web and mobile development, and those are the hottest areas so that's a good start.
Some random examples of contests and competitions that I've been involved with recently include Mozilla Ignite [1], The Great Canadian Appathon [2], and a bunch of other low-key contests with smaller payoffs, often aimed at students. I'm linking to the prize pages just to show you that it can be very lucrative :).
So get out there and give it a shot. At worst you make no money but meet a bunch of awesome people, and they usually present opportunities of their own.
[1] https://blog.mozillaignite.org/2012/09/ideation-winners/
[2] http://greatcanadianappathon.com/prizes.php