T3 did a great article on this exact topic, but with the Storm included. Below is the article, and it lists all of the technical dimensions. They all have basically the same operating system, except for the storm, which has an updated system that is touch capable.

So just find the one with the features you want, and go with that.

BlackBerry Battle: Storm vs Bold vs Pearl vs Curve

Four phones vying to be the business for your business, but which has the best spec?

The BlackBerry Storm was announced today, bringing with it BlackBerry's first serious stab at the consumer market. It looks like an iPhone, it has a touchscreen like an iPhone and when Vodafone launched the website this morning, it even sported the same OS as an iPhone! Vodafone took a few minutes to spot that little oversight though, but it looks like they managed to pull it before Apple's lawyers got out of bed.

But where BlackBerry doesn't have to compete with Apple is on the push email service. In short, BlackBerry's works, and MobileMe is, well, best left unmentioned. Thus Storm has to battle it out with other BlackBerry devices for the best mobile emailer crown. So without further ado, let the spec battle commence:

Dimensions:

BlackBerry Storm 9500: 112.5mm x 62.2 mm x 13.95 mm (length x width x depth), weighs 155g

BlackBerry Bold 9000: 114mm x 66mm x 15mm, weighs 136g

BlackBerry Pearl 8110: 107mm x 50mm x 14.5mm thick, weighs 91g

BlackBerry Curve 8310: 107mm x 60mm x 15.5mm, weighs 111g

Display:

BlackBerry Storm: 480 x 360 pixel TFT LCD, 65k colours

BlackBerry Bold: 480 x 320 pixel TFT LCD, 65k colours

BlackBerry Pearl: 240 x 260 pixels, 38mm x 40mm TFT LCD, 65k colours

BlackBerry Curve: 320 x 240 resolution, 50mm x 37mm, 65k colours

Storage Capacity:

Storm: 128MB on board, plus expandable MicroSD up to 16GB (allegedly)

Bold: 1GB on board, plus expandable MicroSD up to 8GB

Pearl: 64MB on board, plus expandable MicroSD

Curve: 64MB on board, plus expandable MicroSD

Camera:

Storm: 3.2 megapixel with LED flash, zoom and video recording

Bold: 2.0 megapixel with LED flash, 5x digital zoom and video recording

Pearl: 2.0 megapixel with LED flash and video recording

Curve: 2.0-megapixel camera with LED flash, 5x digital zoom, video recording

Connectivity:

Storm: 3G HSDPA, GPS, A2DP Bluetooth with AVRCP (no WiFi!)

Bold: 3G HSDPA, GPS, WiFi, A2DP Bluetooth with AVRCP

Pearl: GPRS, EDGE, GPS, Bluetooth

Curve: GPRS, EDGE, GPS, WiFi, A2DP Bluetooth

Interface:

Storm: Multi-touch touchscreen with haptic feedback (plus copy and paste!)

Bold: Full QWERTY keypad and trackball

Pearl: SureType QWERTY keypad and trackball

Curve: Full QWERTY keypad and trackball

Battery:

Storm: 15 days standby, 5.5 hours talk time

Bold: 13 days standby, 5 hours talk time

Pearl: 15 days standby, 4 hours talk time

Curve: 17 days standby, 4 hours talk time

Media player:

Storm: MP3, AAC, AAC+, eAAC+, WMA, WMA ProPlus audio; MPEG4 H.263, MPEG4 Part 2 Simple Profile, H.264, WMV video (plus 3.5mm output)

Bold: .3gp, MP3, WMA9 (.wma/.asf), WMA9 Pro/WMA 10, MIDI, AMR-NB, Professional AAC/AAC+/eAAC+ audio, DivX 4, DivX 5/6 partially supported, XviD partially supported, H.263, H.264, WMV3 video (plus 3.5mm output)

Pearl: MP3, AAC audio, MPEG-4 and H.263 video

Curve: MP3, WMA, AAC audio, MPEG-4 and H.263 video