I have a Cyber Pokéball. ^_^
They are fun - if you like Pokémon.
I got mine in 2005, and the battery is still going, though I don't know if they have a dowload feature.
At the beginning of the game, you must choose one of the four Pokémons (I chose Pikachu :p) and you have to train it basically. You take it to explore through the world, and you try to capture or defeat any Pokémons you come across.
In Battle Mode, you try to win and get a trophy, and it opens a new section of the world which has new Pokémon to be caught and all that, so you must continue training your Poke so it gets stronger, and can win at battle mode.
You can also connect to other Pokémons in battle mode, but I haven't tried that.
If you finish and beat all Battle mode (that is, you have unlocked all the six parts of the world) you can't play in Battle mode anymore, but Tournament mode is available. You go through 5 or 6 rounds defeating Pokémons, and then you win a kind of belt. XD
The last icon is the Poké list with a list with all the Pokémon you have encountered. If you have caught one, you can also see its weight, its length, its name and its powers.
You can also choose the language you want it to be in, but I don't think it works! If I choose German, the language part is still in English, and anyway, there are no words in it. XD
They are fun, although I haven't opened it recently.
I would suggest getting it only if you like Pokémon, but I heard Pokédexes were better. The design of Pokéball V2 is more attractive in my opinion too.