here's another connection i found

"These screenshots show an easter egg in HEROES where Nikki/Jessica is holding a brochure from the same exact rental car company as the folks in LOST. Does this mean the 2 shows are somehow connected? .... unlikely, but the producers sure are having a good time."

Tim kring and damon lindelof (creator of lost) are good friends
Greg Grunberg was a pilot in the first lost episode
Peter and Boone really look alike
Two cute blonde claires who are kinda short
Niki and Shannon are the mean sexy ones
Micah and DL, michael and walt
both have characters who have separate stories but are connected
two drug addicts
DHARMA, primatech, notice something?

Hiro and Locke also both work in cubicles and have the same uniform
There are two people who are or were in wheelchairs: Heidi Petrelli and Locke
Linderman and Alvar Hanso
Two Asians who learn to speak English and are accompanied by someone who does
Peter and Jack work in hospitals
Spoiler : Two female characters are shot by accident

I noticed a similarity between the way they focus on the characters of Jack and Peter.
In both shows, you can't exactly say that there's a main character, since everyone is focused upon, but if one had to choose a main character for the shows, it'd be those two guys, wouldn't it?

The series begins focusing on them and the ..."burden" of the shows (i.e, surviving on the island, stopping the bomb) seems to be laid more heavily on them than the other characters.

Oh, yeah! They keep on coming.

Matt and Ana Lucia are both cops who ended up turning in their badges.
LOST spoiler:

Libby and Nikki are two blonde girls who were in the psych ward.

Claire and Nikki both had to raise sons when the father left
This is just a theory for the Lost part, but:
Two characters are unexpectedly Claire : Claire, Nathan (and Peter); there's a theory that Jack and the LOST Claire are brother and sister
There is a scene with an intimidating Asian business-man father : Mr. Nakamura , Mr. Paik (Sun's father)
And those two Asian businessmen are theorized to have something to do with the government conspiracy of the show : Mr. Nakamura ( HRG accomplice?) Mr. Paik, ( DHARMA exec.?)
The two youngest boys have unexpected special abilities: Micah and Walt

LOST spoiler:

They both have something to do with time travel and offer a glimpse into the future:
Hiro's teleporting and Isaac's paintings, Desmond's visions

Both have references to famous " Star" sci-fi franchises: Hiro " Like Star Trek".... Hurley" Dude, that was like a .. Jedi moment..."

.... much more to come in future episodes!!

That Asian chick Jack hooked up with said she has powers! Haha!

So that's 3 Lost people with powers: Walt, Desmond, Asian Chick.


Oh yeah! Claire-bear you pointed it out! But my observation's off-topic..
Micah and DL, Michael and Walt...
DL = DisneyLand... Walt.. Disney?
Micah, the name stemming from Michael? Hahaha!

Hey that's right! Both shows involve lists!

There's the list of those with abilities

And the list of those whom the hostiles will abduct.


SPOILER

I'll wrap both of these in spoiler tags:

[spoiler] Both shows mention that something seemingly horrible has to happen. During the eighth episode of LOST when Desmond traveled back in time, the jeweler said that Desmond would have to land on the island and experience all those years pushing the button. Linderman mentions that the explosion has to happen in ep 19 to unite people together.[/spoiler]

I guess it's the whole "fate" thing.

Walt's comic book, similar to Isaac's Hiro comic. and the character Charlie.