If I am entering a number of times as minutes and seconds, I prefer to
use the numeric keypad and enter them using a decimal point rather than
the colon (as Pat says, you have to enter 0:minutes:seconds, which is a
bit tedious). You can then convert this into acceptable time format in
another column.

So, for example, assume you enter your data into column C, starting at
C2, then put this formula in D2:

=VALUE("0:"&INT(C2)&":"&MOD(C2,1)*100)

and format the cell using custom set to [m]:ss. You can then copy this
formula down several rows.

Now if you have a time like 10:33, you enter 10.33 in column C and this
will be converted to time format in column D. Once you have entered the
data, you can fix the values in column D using paste special and
values, and then delete column C.

Hope this helps.

Pete