Multiple LEDs on one switch?

[arashink]

If I were to wire two LEDs to one switch, will I need additional batteries on the same circuit? Are there any other considerations I missed?

Thanks!

[madmaxx]

from messing around with LEDs lately i found out that you can wire afew to one source if they are all in parallel. that is as long as the voltage is about 3 to 3.5v.I also wired three LEDs in series to a 7.4v source and didn't need a resistor and even wired two lots of three series LEDs to the same 7.4v source.they just draw more mA than one will.Have a look at this http://www.kpsec.freeuk.com/components/led.htm and it will explain it better than i can