The problem with those switching dc-dc converters would be the noise on the output, it wouldn't suprise me to see +/- 10-40mV on the output, especially at the low currents the thread author mentions (50mA and up) ... some of those regulators even need a minimum of 1-5mA to function properly (and often those cheap eBay boards don't have "built in" minimum load)
I can't think of anything off the shelf that would do your requirements (0..1v with a relatively decent amount of control, and at low currents like 50mA).
Seems like small linear regulators with very low voltage drop would be ideal for this though and you could probably protect the output using some sort of zener diode or optionally disabling the regulator by setting the regulator's enable (if it has any) line high/low if the voltage goes above 1v.
If you don't really need 0v but you could settle for a minimum of 0.25v or something like that, there are small linear regulators that have internal voltage references smaller than the typical 1.25v
For example a 3$
LT3020 has an internal voltage reference of 0.2v so you can output 0.2...1v but at
maximum 100mA and maximum 10v input voltage (you can just use a 2.5v or 3.3v fixed linear regulator in front of this chip or a cheap mc34063 solution or another dc-dc converter to make sure the voltage is always low enough for this chip)
A 4.5$
LT3021 can do up to around 550mA and it's easier to solder (SOIC, 8 easy to solder leads) but otherwise has the same pros (0.2v minimum) but also same limitations.
A <1$ Microchip (former Micrel)
MIC47053 will do 0.4..1v at up to 500mA but it's even pickier about the input voltage (shouldn't use more than 3.6v) and it would be somewhat difficult to solder. Maybe you can find it in other packages at other stores, I only checked Digikey.
MIC59300 is more expensive at around 3$ but it's quite easy to solder and would allow you to go for high currents (up to 3A) and has internal voltage reference of 0.5v so it gives you directly 0.5 .. 1v . It also works with low input voltages (up to 3.8v) so you'd have to use a regulator before it to give it the low voltage it needs.
Digikey is quite good at this, you can go on the linear regulators page, filter by "positive" and "adjustable" and combinations of these words, then filter by minimum output voltage to see the regulators that can output much lower than 1v without messing around.