The Time Quick Pick buttons, right under the Duration field, can be used to modify the duration without even bringing up the wheel.
The time amount on the buttons can be customized from Setup->General->Time Quick Pick.
Doesn't this just add the increments to the current time? For example, 8:56 AM + 1hr would give you 9:56 AM? I need to have the logged time itself rounded to half hour increments, so, for example, if I start at 8:55 AM and finish at 1:20 PM, the time is reported as 9:00 AM to 1:30 PM. Is there any way to do this? Under the current behavior I have to fiddle with the minutes dial for both the start time and the stop time, which is a big pain.
Also, is there even a way to see the logged start and stop times for multiple time entries, such as on the Time Entries page, or in a time sheet report? All I can see is the total time, but I need more detail, and going into the time entries individually is a hassle when I have to log in and out times for several jobs at once.