skipping gears?

ok heres my question, If im taking off from a stop at say a light, and i use 1st gear until is at about 3000 rpm's (about 20m miles an hour) and i push the clutch in and shift it into 2nd, but not let the clutch out and then shift it in to 3rd so my rpms about match, and just accelerate to 30 or so an crusie at this speed is that bad or harmful on amything? I've been doing this for a while now, i also do it when say i have to decelerate a little, say im in 4th and goin about 45 of 50 and i have to slow to 30 or 35, and i leave it in 4th so when i let my clutch out the rpms match better. Does this harm anything? I had a guy tell me it will wear out my tranny faster than normal wear will, and i had another guy (who i trust just a little bit more) tell me that it was fine, he said it doesnt wear on your tranny, and its a hell of a lot better on my clutch. which guy is wrong?
Thanks,
Jess

nope, i do the same thing

Awesome, thanks for the piece of mind, I appreciate it alot.

Thanks,
Jess