Is It Worth It to Mine Cryptocoins?
As a hobby venture, yes, cryptocoin mining can generate a small income of perhaps a dollar or two per day. In particular, the digital currencies mentioned above are very accessible for regular people to mine, and a person can recoup $1000 in hardware costs in about 18-24 months.
As a second income, no, cryptocoin mining is not a reliable way to make substantial money for most people. The profit from mining cryptocoins only becomes significant when someone is willing to invest $3000-$5000 in up-front hardware costs, at which time you could potentially earn $50 per day or more.