Following up on round up of consoles, let's take a look at the portables.

Gaming Laptop
-See Gaming PC

Sony Playstation Portable

Advantages
-Best graphics our of all current portables, equivalent to early PS2 games.
-Large library of games that are geared toward intermediate and hardcore gamers
-Excellent personal media player capabilities, boxed movies available
-Playstation Store for downloadable games and DLC expansion packs
-Conventional control scheme
-Cheapest current generation portable at $169 for Core system with $199 bundle packs that offer excellent value
-Backwards compatible with original Playstation games
-Skype service on PSP-2000 and up
-802.11b wireless internet for ad-hoc or network play, Internet browser and RSS 2.0 reader
-Connectivity with PS3 allows media streaming
-Unlimited number of saves on flash cards

Disadvantages
-Mediocre battery life
-Few new games being produced for system
-UMD drive slow
-Proprietary Memory Stick Pro Duo memory cards are expensive. Core model does not ship with memory card.
-Analogue stick can be awkward to use. No second analogue stick means players can sometimes encounter game camera control issues.

Nintendo DSi

Advantages
-Large library of family and non-gamer friendly titles including those from Nintendo's hit series.
-Innovative touch screen control combined with conventional control layout
-Excellent battery life
-Flash based game cards virtually eliminate load times, makes games more portable
-Built-in VGA camera for taking pictures
-Ad Hoc wireless play
-DSiware store provides downloadable games
-SD Card slot allows games to be stored, as well as provides MP3 playback.
-Graphics on par with Nintendo 64

Disadvantages
-Poor value. Costs $199.99 in Canada for just the system itself, while PSP bundles provide the system, two games, and a movie for same price.
-Limited number of games that appeal to intermediate and hardcore gamers
-Music playback vary limited, no video playback
-Built in wireless uses legacy 802.11 speeds. Too slow for internet access.
-No longer backwards compatible with Gameboy Advance games. Not compatible with Guitar Hero World Tour and other DS peripherals that use the GBA expansion slot.
-Lowest screen resolution of all portables. 256x192 compared to 480x272 on the PSP and 480x320 on the iPhone
-Some may dislike use of dual screens, stylus, and microphone in gameplay.
-Game saves directly on game cards. Vary limited number of saves.
-Does not come with SD card

Apple iPhone / iPod Touch

Advantages
-Highest resolution screen of all portables
-All games downloadable for instant play
-Excellent media and web functions, iPhone is also a phone and GPS unit. Full featured video iPod.
-Wide variety of non-gaming apps available, can be used as a MID or PDA.
-Games appeal to non-gamers
-Fast built in 802.11g wifi. iPhone has 3G networking for fast mobile connectivity.
-Innovative motion controls

Disadvantages
-Most expensive of all current generation handhelds. $199 for iPhone but requires mandatory 3yr contract with cell company. Touch costs $229.
-Worst graphics of the current generation
-Most games are primitive, highest amount of shovelware than any other system. Limited support from major game publishers. Limited appeal to most gamers.
-Lack of expandable storage limits how many games can be stored on the device at one time
-Mediocre battery life when gaming
-No online play
-Touch screen controls vary limited and often awkward to use
-Games can only be downloaded over Wifi connection or through iTunes; not 3G.