Here are some instances just in the last match by India:
25.4 Harbhajan Singh to Ponting, no run, Ponting moves his front pad outside the line of off stump and tries to sweep, he misses and the Indians appeal once the ball hits the pad, rather optimistic that was
30.4 Singh to Symonds, no run, full-length delivery pitches outside leg stump and thuds into Symonds' pads after he misses the flick, the slips appeal but the ball pitched outside leg
47.5 Kumble to Hogg, 2 runs, Kumble appeals for leg before but hogg was well forward and the impact was outside the line of off stump
60.5 Kumble to Hogg, no run, the least convincing appeal ever for an edge to bat pad, a good catch from Jaffer but there was no wood there, as the fielders seem to know by their wan appeal
41.4 Kumble to Hayden, no run, another loud appeal for lbw as Hayden misses the sweep, he was hit on the pad just outside the line of off stump
Why did they appeal? Every bowler in every match of cricket that I've watched (hundreds by now), has appealed for stuff like this.