If the battery is legitimately dead, you'll literally have to pry open the cartridge and replace it with a watch battery. However, there was a glitch that occurred in some copies of the game known as the "berry glitch", where games with batteries that weren't actually dead stopped working for no particular reason.

If your problem is the berry glitch and not actually a dead battery, there are several different methods to fix this. Look here for a list of them: http://bit.ly/qup5qU

Only if you imagine they do.

Normally, when you go to the gym, you'll fight the elemental monkey that's string to your starting pokemon. Before heading to the gym, look around in the Dreamyard near Striaton City and you'll find a girl who will offer you one of the 3 monkeys. You won't have a choice which one you get, but it'll be the one that's weak to the gym leaders. If you want the other ones, your best bet is to trade.

Mudkips? I LUUUUUUUUUUUURVE MUDKIPS.

I'm pretty sure that Master ball is in a league of its own.

Some stores have mystery events from time to time, and you can only get the gift if you visit the store. That's exactly why in the DS games, there's an option to receive a Gift via local wireless in addition to WiFi.

Because it looks like a bird, I guess. The more important question is "why is Gyarados a flying type?"

Nope. At the moment, the only two pokemon like that are Sableye and Spiritomb.

There are 135 Pokemon that are tied for the title of slowest experience gain. Rather then me listing them all off, here's a list of which 135 they are: http://bit.ly/roWBxG

Fast Balls and a move like Scary Face are the best bet to keep them from constantly running away before you do anything.

When you received certain Mystery Gifts at Nintendo events, it was supposed to alter the cave and change what you encountered. However, Nintendo never actually held a single event in any country that took advantage of this area.

There have already been several official Pokemon titles for PC, although none of them have been developed by Nintendo (although Nintendo did approve them).
Out of the dozen or so, they included Pokemon Project Studio Red and Blue, which let you print various cards and posters with artwork, PokeROMs, a series of educational games, and Pokemon Masters Arena, a minigame collection based off the Ruby/Sapphire arc of the anime.

Shuckle currently holds the highest Defense stat among all the Pokémon in the game with 230.

Starting Pokemon Red over three times because I didn't realize I had to go back to Pallet in order to make the old man stop sleeping on the road in Viridian.

2nd. I'm not explaining why though.

My personal favorite was the glitch in the older games where you could fish and surf in the statues.

Hack it. That's obviously the easiest way.

I remember Blue sold more then Red, and Gold sold more then Silver. Game sales wise, that's all I know. As for pokemon, probably Pikachu.

Yeah, under normal circumstances, you'll have to.

Very Carefully