Preparing for a terrorist attack means getting your portfolio in order, too.

Today's apparent terrorist attack in London, the second in two weeks, rattled a few nerves. In response to listener email, James Cramer spent his

"RealMoney" radio show cobbling together a portfolio designed to withstand a terror attack.

In the category of surveillance companies, Cramer named

L-3

(LLL) - Get Report

,

ThermoElectron

(TMO) - Get Report

and the small-cap

Global E-Point

( GEPT).

In the biochemical-biothreat arena, he cited

Cepheid

(CPHD)

,

RAE Systems

( RAE) and

Hollis-Eden Pharmacueticals

( HEPH).

In IT security, he pointed to

RSA Security

( RSAS),

CACI International

(CAI) - Get Report

,

Internet Security Systems

( ISSX) and

Mantech

(MANT) - Get Report

.

And in identity verification, Cramer rattled off

Visage

( VISG),

ActivCard

( ACTI),

Identix

( IDNX),

Washington Group

( WGII) and

Tetra Technologies

(TTI) - Get Report

.

Why these companies? They are all integral to our security, said Cramer. So until they come up with an exchange-traded fund based on homeland security stocks, you can use these names to create a basket on your own.

Stump Cramer

The first caller attempted to stump Cramer with

Inter-Tel

(INTL) - Get Report

. But Cramer recognized it as a company whose stock symbol is sometiems confused with chipmaker

Intel

(INTC) - Get Report

.

That next caller tried to stump Cramer with

Composite Technologies

(CPTCQ)

. Unfortunately, as Cramer pointed out, that company is in bankruptcy.

Cramer may have been tired from his big special last night, because four straight callers then stumped him with

Synagro Technologies

( SYGR),

MTM Technologies

(MTMC)

,

Comstock Homebuilding

(CHCI) - Get Report

and

Access Integrated Technologies

( AIX).

Cramer's Callers

In a response to a question about

Harmon International

(HAR)

, Cramer said it's a very expensive stock, but he likes it.

On the other hand, Cramer said

Skyworks Solutions

(SWKS) - Get Report

is not expensive at all, plus it has a decent risk-reward ratio. "It's levered to

Motorola

( MOT), so it should be doing very well," Cramer said.

Cramer called

Broadcom

(BRCM)

"the best tech company out there, but maybe not the best stock because it sells at 33 times earnings." He suggested interested investors buy half before earnings and half after.

Cramer said today's big winner,

eBay

(EBAY) - Get Report

, should move up to $50 a share from around $42. He said eBay's quarter was reminiscent of the old days. "The stock has lost the cloud over its head," Cramer said.

Finally, Cramer said he's giving

Comcast

(CMCSA) - Get Report

one more quarter to prove itself before he unloads it. He has lost patience in the stock. "If it had a high dividend yield then I would put up with it, but it doesn't and business may be good but the stock has not shown it," Cramer said.

At the time of publication, Cramer was long Comcast, Intel and Motorola.

James J. Cramer is a director and co-founder of TheStreet.com. He contributes daily market commentary for TheStreet.com's sites and serves as an adviser to the company's CEO. Outside contributing columnists for TheStreet.com and RealMoney.com, including Cramer, may, from time to time, write about stocks in which they have a position. In such cases, appropriate disclosure is made. To see his personal portfolio and find out what trades Cramer will make before he makes them, sign up for

Action Alerts PLUS. While he cannot provide personalized investment advice or recommendations, he invites you to send comments on his column by

clicking here. Listen to Cramer's RealMoney Radio show on your computer; just click

here. Watch Cramer on "Mad Money" at 6 p.m. ET weeknights on CNBC. Click

here to order Cramer's latest book, "Real Money: Sane Investing in an Insane World," click

here to get his second book, "You Got Screwed!" and click

here to order Cramer's autobiography, "Confessions of a Street Addict."