i just shove 8 AA's into my radio, and it works fine. the radio will display low battery at 1.1v ish anyway, so it's not a problem with ni-mh's. standard alkalines are a weird battery, the capactiy depends on the draw. a 10mah draw will mean the battery has a 3000mah capactiy, but a 500mah draw like on a radio will mean they drop to abut 1000mah. (or less. try putting some in a digital camera!)

if you're still concerned, just look at the price differential. 4 nimh AA's: £2 (value supermarkets ftw)

10 alkalines: £4

seeing the look on your freind's faces when you tell him you never buy batteries: priceless