Everything's coming up Jack Dorsey these days. Last week Apple started stocking Square's iPhone credit card readers in its 235 US retail locations, and now, according to Reuters, Visa has put its plastic where its mouth is. The credit card giant has invested in the personal payments startup, scoring itself a spot on Square's advisory board in the process. No word on how much Visa is actually dropping on the company, but one thing stands to reason: it probably didn't make the deposit via Verifone. If you would like to invest in a Square reader, it'll cost you a lot less -- the company is still offering smartphone plug-ins for free on its site.